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The Fauna and Geographyof theMaldive andLaccadive ArchipelagoesVOLUME II.PART II.

Hontion: C. J. CLAY and SONS,CAMBRIDGE UNIVERSITY PRESS WAREHOUSE,AVE MAMA LANE,ANDH. K. LEWIS,136, GOWER STREET, W.C.M

The Fauna and Geographyof theMaldive and Laccadive ArchipelagoesBeing the Account of the Work carried on andof the Collections made by an Expeditionduring the years 1899 and 1900EditedbyJ.Stanley Gardiner, M.A.Fellow of Gonville and Caius College and late Balfour Studentof the University of Cambridge.VOLUME II.PART II.With Plates XXXV—XLVIII and Text-Illustrations 120—126.Cambridge :at the University Press.1903

:CAMBRIDGEPRINTED BY J. AND C. F. CLAY,AT THE UNIVERSITY PRESS.

CONTENTS OF VOL. II.PAKT II.Reports.1. Marine Mollusca. With Plates XXXV and XXXVI .PAGE. . 589By Edgar A.Smith, I.S.O.2. The Enteropneusta. With Plates XXXVII—XLVI and Text-Figs. 120 and 121 631By R. C. PuNNETT, M.A.3. Marine Crustaceans. X. The Spider-Crabs (Oxyrhyncha). XI. Onthe Classification and Genealogy of the Reptant Decapods.With Plates XLVII and XLVIII and Text-Figs. 122—126 . 681By L. A. BORRADAILE, M.A.

MARINEMOLLUSCA.By Edgar A. Smith, I.S.O.(With PlatesXXXV. and XXXVI.)As the first collection of Marine Mollusca of any importance that has hitherto beenobtained at the Maldive Islands, that about to be described is of considerable interest. Itconsists of about 380 different species and probably comjorises a large proportion of theforms which occur in these islands. That many have escaped notice and will eventually becollected by others is quite certain, but it seems probable that most of the larger speciesare represented in this collection and that it is only among the smaller and obscurer formsthat many additional species will hereafter be discovered.\^ There are, however, certain common and widely distributed species which one wouldhave expected to have been found, notably belonging to the genera Conus, Terebra, Sistrum,Purpura, Nassa, Oliva, Solarium, Truchus and Circe. It is also worthy of remark thatcertain genera which have representatives in the surrounding seas do not aj^pear to havebeen met with. Of these I may mention Fasciolaria, Rissoa, Patella, Eulinia, Hydatina,Aplysia,Umbraculiim and Mytilus.As might be expected the fauna is similar to that of other islands in the IndianOcean, many of the species occurring in Ceylon, Mauritius, Madagascar, the Amirantes,Seychelles, and a great many ranging as far north as the Red Sea and Persian GulfRather more than a seventh of the forms have been recorded from the Andamans, andprobably many others occur at these and the neighbouring Nicobar group. It is well knownthat great numbers of marine molluscs have a very wide range, and therefore it is notsurprising that many, in fact about three-fourths, of the Maldive shells are kno\vn to occurin the seas surrounding the Philippine Islands and the Malay Archipelago, and still furthernorth about one-fourth of the species have been recorded from the islands of Japan. Inthe Pacific, from the East coast of Australia to the Loyalty Islands and Polynesia, ratherover three-sevenths of the Maldive species have been recorded, many of them ranging allover both the Indian Ocean and the Malay region also. About one-third of the speciesare known from Ceylon, but doubtless many more occur there, although they may not havebeen recorded. About 177 species have been found at the Mauritius, the fauna of whichhas been more extensively worked than that of the Seychelles. With regard to the generaldistribution of the species about to be recorded, it is curious to observe that a largerprojjortion of them have previously been noted from the China Sea eastward and in thePacific, than in the Indian Ocean, including the Red Sea and Persian GulfThe following table shows at a glance the distribution of the species as far as thewriter has been able to ascertain without a very exhaustive search. The column underMalaysia includes species which occur in the China Sea, the Philippine Islands, MalayArchipelago, N. Australia, New Guinea, and as far east as the Solomon Islands. UnderPol\Tiesia are indicated the species which are met with either in E. Australia or at theLoyalty Islands, or at the various groups of islands of Polynesia.G. II. 76

..590 EDGAR A. SMITH.60at3aso-73a

MARINE MOLLUSCA. 591a•c s1^sJ3§?T3 Cli02 OOoTerebra iDiihilnta+,, ojfinis„ cohiiiiellaris,, hrii(]iiieri,, amaina,, violasceiis„ lanceata„ celidonotaPleurotoviaarmillata„ lijubnta„ tUirinaDrillia e.raspenitaClathurellarobillardiDaphnella saturataOliva erythrostomaHarpa ventricosa,, minor+++++++++++++MaryineHa picturiitaMitra episcopalis++++,, pontificalis++,, tessellata„ adustu,, digitalis„ crenifera„ scabriiiscula,, rarii'nata,, ciietiuwrina,, fihu'is,, insculpta„ interlirata,, Uterata,, acuminata,, auriculoides,, exasperata„ sculptilis„ ueiipicta,, tiniiigera„ deshayesii,, angugtissima, n. sp.Gylindra sinensisLatirus craticulatus,,fastigiumPeristernia nassatula+++++++++++++

—592 EDGAR A. SMITH.3 SC3dSaitnhercularis,, hippocastanumpica++++++lopan situla,, sertmnSistrum digitatuiithorridum++++++++

MAEINE MOLLUSCA. 59313 aa oj3Sistrum ricinus,, tuberculatiuit„ undatum,, elatum+++.aa++++++,, spinosum,, hlcoiiiciun„ cavernosum, , iostonia„ squamosum,, concatenahim„ decussatumCoralliophilamonodonta,,neritoidea„ suturalis„ squamosissiniaLeptoconchus ellipticusciiiiiingii,,Lotorlum chlorostoma„ gemmatumpyrum,,,, tuberosum++++++Colubraria ceylonensis„ obscura,,bracteata„ digitaleDistortrix aimsRanella bufonia,, granifera,, lampas+++++++++++,, tuberosissima,, thomaeCassis cornuta+++„ rujaMalea pomum++Dolium costatmn+,, oleariumPirula ficoidesCypriea annuhis+++++++arabicaargus++++++aselluscaput-serpentiscameola++++++++

,594 EDGAR A. SMITH.3-a ao5j,Moss3°Gypr(vacaurica++„ clandestinn„ cribrarin„ erosa„ felina„ gangrenosa,,globulus,, hclvola++++++'++++++++++++++++++„ liinmdo++++,, Isabella++++,, laniarckii+++„ liin.v,, mauritiana,, minoridens+++++++++++++++,, moneta, ,poraria,, staphylceatalpa, , tigris, , ,, vitellus+++++++++++++++++++++++++++++++++„ walkeri++,, ziczac+Trivia ^'^Huoidula+Strombus dentatus,floridus++,, gibberulus ..._„ labiosus+++++,, lentiginosus++,, guttatiis+,, lamarckii++Pteroceralambis++,, chiragra++Terebellum terebellumTriforis corrugatns+++„ elegans+„ sculptits+„ liiaceocinctus, n. sp.„ excellens, n. sp,, gracilis, n. sp,, ^JM7-a, n. spVertagus articulatus+,, fasciatus+„ kochi+ +

MARINE MOLLUSCA. 595!^%S13-35 CJa

.596 EDGAR A. SMITH.3oa o"?!00 >iIdP3tSa

MARINE MOLLUSCA. 597

598 EDGAR A. SMITH.3isaa'a

MARINE MOLLUSCA. 599Ifc has been noticed in other groups of animals that the specimens collected at theMaldives have a tendency to be smaller than those found upon the shores of the mainlandand Ceylon. This peculiarity also to a certain extent is noticeable among the Mollusca, or,at all events, the representatives of many species are small in comparison with the largerdimensions they often attain.No attempt has been made to give full synonymy or many references to illustrations,but it has been thought advisable, in each case, to quote a figure or a description, so asto show what species was really referred to. This is necessary in some instances where anauthor's species has been differently interpreted by his successors, as, for example, in thecase of Strombus auris-dianae of Linn^, where Reeve's and Deshayes' view of this speciesis quite the reverse of that held by Sowerby.In the account of the numerous species hereafter mentioned the localities where theywere obtained are referred to under numbers only which are explained in the following listof stations.I.

600 EDGAR A. SMITH.Family ACTAEONIDAE.1. Solidula glabra, Reeve, var. 37, XV. {Holidula sulcata, Pilsbry (nee Vohita sulcata, Giiielin),34:, xr.) X, XV.In my opinion this is not the Valuta sulcata of Gmelin, as stated by Martens and Pilsbry.The name sulcata practically proves this, and a reference to the grooved figures in the Conchylien-Cabinet upon which the species was founded also shows that it is quite distinct from Keeve'sTomatella glabra. Moreover Martini (Conch. Cab. vol. ii. p. 124) described his shell as being" tief gefurchet," a character not at all applicable to the present species but admirably suiting thewell-known Solidula solidula (Linn.) with which, in my opinion, the V. sulcata, is synonymous.The specimens from the above stations are small and slender.2. Solidula nitidula, Lamk. 34, AT. IX, XY.3. Solidula solidula, Linn., var. 34, XF. VIII.A single specimen, pure white, with only a few grey dots upon the ridges near the outer lip.4. Solidula tessellata. Reeve, 34, JfF. IX.Family BULLIDAE.5. Bulla ampulla, Linn. 34, XY. II, IX, XLFamily AKERIDAE.6. Volvatella cincta, Nevill, 34, XV. XV.Family SCAPHANDRIDAE.7. Atys cylindrica, Helbling, 34, X V. II.8. Atys naucum, Linn., 34, J F. II, III, V, IX.9. Atys succisa, Ehrenberg, 40, a, XVII., 1, c. XV.It is uncertain whether the shells figured by Adams and Sowerby truly represent Ehrenberg'sspecies, but it is equally certain that they do not belong to A. cylindrica as stated by Pilsbry.The latter has made a curious mistake in connection with A. succisa {Man. Conch, vol. xv. p. 267).He states, " There is the trace of a median gibbosity," whereas Ehrenberg distinctly says it isabsent, " gibberis vestigium in zona media deest."Family OXYNOEIDAE.10. Oxynoe delicatula, Nevill, 34, XV. XV.FamilyPHILINIDAE.11. Cryptophthalmus minikoiensis, n. sp. (PI. XXXV. figs. 1, 2). XV.Animal corpore oblongo, angusto ; discus capitalis parte corporis reliqua brevior, bipartitus, parteanteriori scutiformi, antice bimarginata, truncata, postice angustata, bilobata, parte posteriori postice

MARINE MOLLUSCA. 601truncata, ad latera cavinata et lamellata;pes infra orem leviter sinuatus, ad angulos rotundatus,extensionibus lateralibus semicircularibus, sed in exemplo singulo supra tergum reflexis ; testa minima,ad extremitatem corporis posticam posita, cute tenuissima tecta, tenuis, semipellucida, supra convexa,semiconvoluta, postice acuminata, striis incrementi tenuibus sculpta ; branchiae plumiformes, multilamellatae,sensim versus extremitatem attenuatae, infra testam sitae. Longit. tota 17 inillim.Discus capitalis 7 longus, i latus. Diam. lobis pedis expansis 12 millim. Testa 4 longa, 2^ lata.Closely allied to C. smaragdinus, Leuckart, and differing only in the form of the shell. Thisis exactly the same as that erroneously figured by H. and A. Adams in the Genera of RecentMollusca, vol. III. PI. LViii, figs. 3 a, 3 6, as Chelidonura hirundinina of Quoy and Gaimard. Acomparison of these figures with those of Leuckart' and Ehrenberg- at once shows the considerabledifference in form.The shell of Crypt, luteus, Quoy and Gaimard, is more like that of the present species, butthe short folds on each side of the head-shield do not appear to Vje present in that species, atall events they are not referred to by the authors. The most remarkable character in this speciesconsists in the structure of the cephalic disc. It is, as it were, in two parts, the one superimposedupon the other. The anterior portion is shield-shaped, being broad, truncate, and double-edged infront, and narrowed behind. The converging sides are not, however, united posteriorly, but foi-invery small lobes, attached to the hinder portion of the disc. The latter is squarely truncate behind,keeled at the sides, and exhibits beneath the carinate margins about fifteen shurt oblique lamellae.This is a very striking feature, and occurring in C. smaragdinus, makes one doubtful whetherthe present species, although the shell is very different, is i-eally specifically distinct.Family CONIDAE.12. Conus arenatus, Hwass. 37, /. \'III, IX, XI, XII, XIV, XV.13. Conus betulinus, Linn. 37, /. {C. medusa, Gmelin, 16) IX, XL14. Conus catus, Hwass. 37,/. (var. = C. discrepansl Sowerby, 40, «, var. = C. adansoni,Reeve (now Lamk.), 37,/., var. = C. nigrojmnctatus, Sowerby, 4Xi,h,III.) IX, XV.1.5. Conus ceylonensis, Hwass. 37,/. (var. = C. pusillus, Chemnitz, 37,/., var. = 6'. nanus,Broderip, 37, /) IX.16. Conus distans, Hwass. 37,/. (C. mennonitariim coronatus, Chemnitz, 9) IX.17. Conus eburneus, Hwass. 37,/. IX, XII, XV.18. Conus ermineus, pjorn. 4:0, h, III. (C. lithoglypkus, Meuschen, 37,/. C orleanus, Bolten,30, var. = C. lacimdatu.t, Kieuer, 23, var. = C. carpenteri, Crosse, 11, a) IX.19. Conus flavidus, Lamarck. 37,/. (C. inaltzaaiaiius, Weinkaufl', 43, var. yranulata — C.frigidus, Reeve, 37, /., var. = C. neglectus, Pease, 31, b) XV.20. Conus generalis, Linn. 37,/. (var. =C'. ?;; aWitnts, Hwass. 37,/., var. = 6'. monile, Hwass.37,/., var. = C'. bayani, .Jousseaume, 22, jun. =C. sjnrogloxus, Deshayes, 4:0, b, XII.) XIV.21. Conus glans, Hwass. 37, /. (var. = C. len.uistriatus, Sowerby, 40, b, III, var. = C. fabida,Sowerby, 37,/., var. =C'. scabriuscnlus, Chemnitz, 9) IX.30) IX.22. Conus hebraeus, Linn. 37, /. (var. — C. vermiculatus, Lamarck ; vai'. = C. chaldaeus, Bolten,'See Pilsbry, ihiii. Coiu-h. vol. xvi. PI. vi. tigs. 33-34. - See PUsbry, I.e. fig. 32.

602 EDGAR A. SMITH.23. Conus lividus, Hwass. 37, /. (var. = C. citrinus, Gmelin, 40, 6, ///., var. = C. sanguinolentus,Quoy and Gaimard, 35, var. = C maurus, Gray? 18,6) IX, XL24. Conus miles, Linn. 37, /. IX.25. Conus minimus, Linn. 37, /. {Conus coronatus, Dillwyn (non Gmelin), 43. C. barhadensis,Hwass. ^0,b,III. C. aristophanes (Duclos?), 40,6,7//.) I, XV.26. Conus nussatella, Linn. 37, /. (C terehra, Chemnitz (nee Born), 9). IX.27. Conus pennaceus. Born, 37, /. IX, XI.C. praelatus, Hwass, G. 'rubiginosîs, Hwass, C. ejyiscopus, Hwass, C. omaria, Hwass, C. magnificiis,Reeve, C. elisae, Kiener, C. racemosus, Sowerby, and C. madagascariensis, Sowerby, may beregarded as varieties of this species.28. Conus quercinus, Linn. 37, /. (C. buxeus, Link, 30. C. ponderosus, Beck, 6). II.29. Conus consors, var. 40, 6, ///. (var. = C. innexus, A. Adams, I. 6) I.With this species, besides G. innexus, I also associate, as varieties, C. miceps, A. Adams andC. daullei, Crosse.The single specimen from Addu atoll differs from the typical form of the variety innexus inbeing almost entirely white, and of a slightly more slender form. It is clothed with a thinnishgreyish periostracum and the upper whorls of the spire are finely coronated and of a lilac tint.30. Conus tendineus, Hwass. 40, /. IX.3L Conus tessellatus. Born. 37,/ IV, V, IX, XIV.32. Conus textile, Linn. 37, / IX.The variation in this species is most remarkable, and although we can recognise typical examplesof the many named forms, personally I have not been able to accept as distinct species thefollowing :—C. vicarius, Lamarck, G. verriculum, Reeve, C. textilina, Kiener, C. tigrinus, Sowerby,C. corbida, Sowerby, C. scriptus, Sowerby, C. pannicidii,s, Lamarck, G. canonicus, Hwass, G. rubescens,Bonnet, G. legatus, Lamarck, G . paulucciae, Sowerby, C. archiepiscopus, Hwass, and C. abbas, Hwass.33. Conus tulipa, Linn. 37, / (var. = C. obscurus, Humphreys, 37, /, jun. =-- G. borbonicus,Adams, 2, 42). IX, XI, XV.34. Conus zonatus, Hwass. 37, /. IX.Family TEREBRIDAE.35. Terebra maculata, Linn. 37, XII. IX, XI, XV.36. Terebra argus. Hinds, 37, XII. (Terebra nebulosa, Kiener, 23). IX.37. Terebra dimidiata, Linn. 37, XII. IX.38. Terebra oculata, Lamarck, 37, XII. IX.39. Terebra subulata, Linn. 37, XII. XI.40. Terebra crenulata, Linn. 37, XII. XV.Buccinuni varicosniii, Gmelin, B. luteolum, Martyn, are synonyms and /. fimbriatM, Deshayes,and T. interlineata, Deshayes, I regard as varieties of this species.

1VLA.RINE MOLLUSCA. 603•il. Terebra cingulifera, Lamarck, 37, XII. {Buccinum succinctum, Gmelin, 16. T. punctulata,Sowerby, 40, c. T. punctatostriaia, Gray, 18, «. T. pallida, Deshayes, 12, b. T. chinensis,Deshayes, 12, d). IX, X, XII.42. Terebra babylonia, Lamarck, 37, XII. XIV.43. Terebra monile, Quoy and Gaimard, 37, XII. ILII,44. Terebra (Myurella) undulata. Gray, var. 37, XII. (T. approximata, Deshayes, 12,

604 EDGAR A. SMITH,59. Harpa ventricosa, Linn. 37, /. IX.Family HAEPIDAE.60. Harpa minor, Lamarck, 37,/. IX.A specimen captured by Mr Gardiner at station I. has the hinder portion of the foot detached.Judging from the large size of the separated portion, the animal apparently divested itself of it,being unable to withdraw this bulky appendage within the shell. Or, may it not be cast oft' asa peace offering to any fish or other predatory creature who attacks the helpless ISIollusc ?Family MARGINELLIDAE.61. Marginella picturata, Nevill, var. PI. XXXV. figs. 3, 4 {M. picturata, Weinkauff, 43). X.The two specimens which I believe to be a variety of this species differ from the type inhaving the outer lip strongly denticulate within, in one example the denticles numbering thirteen,in the other only nine. Both are of a fleshy tint, with two white narrow zones with reddishbrownspots upon the penultimate whorl, and three upon the last, one at the suture, one at theslioulder, and one towp,rds the base, all terminating upon the thickened labrum in a red spot.Between the second and third zones there are three or four transverse lines of pinkish red colourand the extreme tip of the spire is also reddish. The brown spots upon the narrow white zonesare small and might be described as cross lines rather than spots.Family MITRIDAE.62. Mitra episcopalis, Linn. 40, 6, lY. XI.63. Mitra pontificalis, Lamarck, 40, h, IV. IX.64. Mitra tessellata, Marty n, 40, 6,/ T. IX.65. Mitra adusta, Lamarck, var. ^0,b,IV. IX.One specimen of a uniform rich brown colour and without any crenulations beneath the sutures.66. Mitra digitalis (Chemnitz), Dillwyn, 40, 6, /F. IX.67. Mitra (Scabricola) crenifera, Lamarck, 40, b, IV. IV.68. Mitra (Scabricola) scabriuscula, Linn. 4:0, h, IV. XL69. Mitra (Scabricola) variegata, Pieeve, 40, 6, /F. II.70. Mitra (Chrysame) cucumerina, Lamarck, 40, 6, IV. IX, XIII, XV.71. Mitra (Cancilla) filaris, Linn. 41, /T. {M. filosa, Born, 40,b,IV.) XL72. Mitra (Cancilla) insculpta, A. Adams, var. 40, b, IV. V, VI.73. Mitra (Cancilla) interlirata. Reeve, 40, 6, IV. II.74. Mitra (Strigatella) literata, Lamarck, 40, 6, /F. IX, XI, XV.>75. Mitra (Strigatella) acuminata, Swainson, 4:0, b, IV. I, IX, XL76. Mitra (Strigatella) auriculoides. Reeve, var. 40, 6,/ F. IX.The two specimens obtained by jNIr Gardiner differ considerably from all the figures given ofthis species. They are much more slender, and the upper part of the shell above the white zone

MARINE MOLLUSCA. 605is white, blotched with dark chestnut. The lower part of the body-whorl is minutely white-dotted.Intermediate forms connecting this with the type occur in the British Museum collection. Length,17 mm., diam. 7 mm.77. Mitra (Costellaria) exasperata, Gmelin, 40, 6, /F. (var. = v¥. arenosa, Lamarck, 40, i, IV.)VII, VIII, IX, X, XII, XIV, XV.The two specimens from station XIV. are variations of the form arenosa, differing from normalexamples in being almost entirely white, with only one or two fiiiut zones below the middle ofthebody-whorl.78. Mitra (Costellaria) sculptilis. Reeve, 37, //. II, V, X.79. Mitra (Costellaria) acupicta. Reeve, 4:0, b, IV. V.80. Mitra (Costellaria) armigera. Reeve, var. 37,11. IX.A single specimen only of this species was obtained. It differs from the type in being whiter,with a thread-like brown line round the middle of the upper whorls and three on the last. Thelocality of the type is unknown. M. turrigera, Reeve, is closely allied, but more sculpturedbetween the costae.81. Mitra (Costellaria) deshayesii, Reeve, 40, b, IV. X.82. Mitra (Costellaria) angustissima, n. sp. (PL XXXV. fig. 5). V.Testa gracillima, elongato-fusiformis, pallide fuscescens, ad partem anfractuum superiorem albida,fusco maculata, et circa medium anfr. ultimi maculis subquadratis notata ; aiifractus circiter 10,superiores subgradati, fere plani, caeteri leviter convexiusculi, costis numerosis (circiter 28) gracilibusinstructi, et sulcis spiralibus inter costas punctatis (in anfr. penult. 7, in ultimo 12—13) sculpti,ultimas antice circa caudam sulcis obliquis fortioribus baud punctatis ornatus ;apertui-a parva, angustalongit. totius J paulo superans ;columella plicis quinque obliquis instructa, callo tenui induta ; labrumtenue. Longit. 12^ mm., diam. 4. Apertura 5 longa, 1^ lata.Remarkable for its very slender form and the punctate striae between the costellae. The foldson the columella correspond to the oblique ridges between the sulci on the cauda of the bodywhorl.These ridges are spotted with pale brown.83. Cylindra sinensis. Reeve, 40, 6,/ F. VI.Family FASCIOLARIIDAE.84. Latirus craticulatus, Linn. (TurbineUa craticulata. Reeve, 37, IV.) IX.85. Latirus fastigium. Reeve {TicrbincUa fastigium, Reeve, 37, IV.) XII.86. Peristernia nassatula, Lamarck (TurbineUa nassatula, Reeve, 37, IV.) IX.87. Leucozonia smaragdula, Liim. (TurbineUa smaragdula. Reeve, 37, IV.) IX, XI, XIII.Family TURBINELLIDAE.88. Cynodonta cornigera, Lamarck (TurbineUa cornigera, Reeve, 37, IV.) Maldives.G. II. 78

606 EDGAR A. SMITH.Family BUCCINIDAE.89. Engina mendicaria, Lamarck {liicinula mendicaria, Reeve, 37,///.) XI.90. Sngina bonasia, Martens {Plicatella {Peristernia) honasia. Martens, 26). IX.91. Engina rawsoni, Melvill (Sistrum rawsoni, Melvill, 27, a). V.The columella is described as "simplice," but all the specimens examined, including the type,exhibit a thin circumscribed callosity, with a small transverse tubercle at the upper end, and afew anteriorly. All also have a pale peripheral zone, and some of the costae are whitish. Inone of the Maldive specimens, white is the predominating tint ; on the contrary, a second exampleis almost entirely of a rich brown colour, excepting the whitish zone round the middle of thebody-whorl, which is rather more contracted and produced anteriorly than usual, the canal, inconsequence, appearing a little longer.92. Phos roseatus. Hinds, 40, b, III. II, lY, V, VI, VII.93. Phos textilis, A. Adams, 40, b, III. V, XIII.The specimens from the above localities are considerably smaller than the type from thePhilippine Islands but do not offer any tangible differences in other respects. The protoconch islarge and consists of three smooth glossy convex yellowish whorls. The normal volutions may varyfrom four-and-a-half to five-and-a-half.Family NASSIDAE.94. Nassa bifaria, Baird, var. 5,39,/. II, IV, V, VII, X.The Maldive specimens belong to the same variety as those from the Andaman Islands whichI recorded and figured at the above reference. Tryon in his absurd craze for "lumping" consideredthis species "a stumpy variety" of X. hirta, Kiener, a species with which it has in fact butslight resemblance, differing in size, colour and sculpture.95. Nassa marratii. Smith, 39, e,/ XI.Two specimens were obtained agreeing with the type excepting in their larger size, being19 mm. in length, like the Andaman examples figured in the P. Z. S.96. Nassa monile, Kiener, 37, VIII. XI.97. Nassa stigmaria, A. Adams, 37, YIII. V, XII, XV.98. Nassa echinata, A. Adams, 37, VIII. IX, X, XII, XV.99. Nassa glans, Linn. Z7,VIII. 111.100. Nassa granifera, Kiener, 37, VIII. IV, VIII, X, XIII, XV.101. Nassa maldivensis, n. sp. (PI. XXXV. tigs. 6—8). VIII, IX, XILTesta N. ahjidae^ similis, sed concolor, albida, anfractu ultimo majori ; lirae aperturae circiter12 et columellae rugae validae. Longit. 25 mm., diam. 15. Apertura cum labro 15 longa, 7 lata.var. a. VIT. Testa minor, anfractu ultimo costato. Longit. 20 mm., diam. 11.Shell ovate, turreted, white ; whorls 6i gradate, upper ones costate, the costae nodose at theupper end through being traversed by a depression or groove, gradually dying out so tliat the1 Nassa algida. Reeve, Con. Icon. vol. viii. figs. 145 a, b.

MARINE MOLLUSCA. 607body-whorl is quite smooth excepting towards the labrum where a few sulci parallel with it aresometimes visible and four or five rather coarse grooves encircle the base. The outer lip is sharpat the edge with four or five denticles anteriorly thickened and Urate within. Lirae twelve innumber, produced within the aperture, tliread-like, not reaching to the edge of the lip. t!olumellatransversely lirate, furnished with a free-edged callosity. The operculum is yellowish, unguiform,with a terminal nucleus, and serrated on each side towards the apex.102. Nassa mulukuensis, n. sp. (PI. XXXV. tigs. 9, 10). VI.Testa iV. maldive^m similis, sed gracilior, anfractibus superioribus spiraliter liratis, operculodiverse instructa.Longit. 24 mm., diam. 12. Apertura V2h longa, 6 lata.Shell elongate-ovate, turreted, whitish, with a few dots and spots of a reddish colour on theupper edge of the whorls, especially on the dorsal margin of the body-whorl. Wliorls 9, the thi-eeapical smooth, glassy, the four following oliliquely costate and transversely sulcate, the groovescausing the costae to be somewhat nodulous. The last two whorls are smooth, excepting thesubsutural row of nodules and a few sulci parallel with the labrum and around the lower partof the body-whorl. The labrum, lirae within and the columellar callosity are as in ]V. maldivensis.The operculum, however, is quite different from that of the species referred to, being ovate,concentric, witti a centi-al nucleus, and having only a few serrations on one (the outer) side.103. Nassa subtranslucida, n. sp. (PI. XXXV. tig. 11). V.Testa elongata, turrita, subpellucida, nitens, albida, maculis et lineis dilute fuscis irregulariterpicta ; anfractus 7, superiores tres laeves, convexiusculi, circa medium carinati, caeteri gradati,convexiusculi, longitudinaliter costati, costis laevibus, crassiusculis, quam interstitiis latioribus, ininterstitiis trasversim striati, ultimus circa basim fortiter sulcatus et nodose liratus, cauda albaoblique sulcata iiLstructus ; apertura intus alba, longit. totius J baud aequans; labrum e.\tra valdeincrassatum, album, maculis duabus fuscis ornatum, intus tenuiter liratum ; columella arouata, callotenui, antice denticulum formante, induta.Longit. 8 mm., diam. 4.This is a shining semipellucid species, rather strongly costate for its size. The last three orfour ribs behind the labrum are obsolete inferiorly, and all are subnodose below the suture, throughbeing crossed by a shallow groove. The colour-markings are irregularly disposed, but the principalspots are upon the upper extremities of some of the costae and at the middle and base of thebody-whorl.10-t. Nassa disparilis, n. sp. (PI. XXXV. fig. 12). V.Testa minima, ovata, alba, lineis rufis duabus circa anfraet. ultimura cincta ; anfractus 7— 8,superiores tres convexiusculi, laeves, politi, circa medium carina filiform! instructi, caeteri longitudinaliteroblique costati (costis in anfr. penult, et antepenult, crassis, circiter 8, in ultimogracilioribus, circiter IG, supra nodosis) inter costas spiraliter distincte sulcati ;apertura parva, longit.totius -I adaequans ; labrum extra varice albo crasso transversim striato instructum, intus liris 9,baud ad marginem productis, munitum ; columella callo circumscripto induta, arcuata, transversimtuberculata.Longit. 7i mm., diam. 4.Only a single example is in the collection. It is remarkalile for the stoutness and small numberof the costae upon the penultimate and antepenultimate whorls in comparison with those upon thelast. The upper extremities are cut across by a distinct groove, thus forming a row of nodules78—2

608 EDGAE A. SMITH.below the suture. Of the two reddish lines upon the last whorl, the upper one is around themiddle, and the other at the base.105. Nassa ecstilba, Melvill and Standen, 28, a. XIV, XV.Family COLUMBELLIDAE.106. Columbella conspersa, Gaskoin, 37, XL II.A single typical specimen.107. Columbella flava, Bruguiere, 37, XI. I, X.108. Columbella jaspidea, Sowerby, Z7,XI. 4:0, b, I. IX.Only a single specimen was obtained. Probably C. plicm-ia, Montrouzier (Jourii. Conch, vol. x,p. 234, pi. IX, fig. 3, 1862) is a varietj' of this species. The specimen figured by Reeve is notmottled or spotted like the type, the latter agreeing in this respect with C. 'plicaria.smooth.109. Columbella galaxlas, Reeve, 37, XT. XV.110. Columbella turturina, Lamarck, 37, X/. IX, XV.111. Columbella varians, Sowerby, var. 40, &, /. 37, XI. IX.A single whitish example with the transverse striae indistinct so that the surface is ratherFamily MURICIDAE.112. Murex ternispina, Lamarck, 37,111. I, VI, X, XIII.113. Murex haustellum, Linn. 37, ///. VI, X.114. Murex (Pteronotus) tripterus. Born. 37,111. V.115. Murex (Chicoreus) aculeatus, Lamarck, 37,111. V, XII.116. Murex (Chicoreus) adustus, Lamarck, 37,111. V, VII.117. Murex (Chicoreus) rubiginosus, Reeve, 37,111. IX.118. Murex (Chicoreus) ramosus, Linn. 37,111. IX.119. Murex (Ocinebra) salmoneus, Melvill and Htanden, 28,6. {Murex pumilus, A. Adams,1,6. 40,6,7F. 39, ,7.) XILThe name pumilus, A. Adams, was preoccupied by Broderip many years previously, hence theemployment of tile name salmoneus. I think there is little doubt that Messrs Melvill and Standenredescribed this species, for examination of the types of both forms shows that they are the samespecies. The single example from the Maldive Islands is dirty whitish, but, being a dead shell,and occupied by a Pagurus, it probably has lost the usual rose-colour.120. Murex (Ocinebra) pleurotomoides, Reeve, 37,111. II.Three specimens rather smaller than the type, with the anterior canal stained with brownand a pale brown zone round the middle of the body-whorl. The lirae within the labrum areabout six in number, and the tubercles on the columella, three or four. The posterior sinus, atthe upper end of the outer lip, seems to be a constant feature.

MARINE MOLLUSCA. f;09121. Murex (Ocinebra) submissus, n. sp. (PI, XXXV. fig. 13). XII.Testa minima, ovata, rimata, supra acuminata, albida, lineis interruptis nigro-fuscis cincta •anfractus 6|, superiores tres laeves, convexi, caeteri supra concave declives, costis longitudinalibusocto et liris spiralibus supra costas elatis (in anfr. penult. 2, in ultimo 8— 9) instructi, incrementilineis tenuissimis striati, ultimus in medio convexiusculus, antice contractus; apertura intus flavescens;labrum extra incrassatum, intus liris brevibus sex baud ad marginem productis munitum ; columellasinuosa, callo tenui reflexo flavescente induta,•in medio prominens, tuberculis parvis 3—4 munitacanalis anterior obliquus, recurvus.Longit. 8i mm., diam. 5.The dark brown transverse lines, about six or seven upon the last whorl, are interruptedbetween the costae, and falling upon the raised lirae, the ribs appear to be crossed by colouredtubercles.The costae are a little oblique and continuous up the spire. The smooth protoconch is markedoff from the first normal whorl by a slender varix or thickened lip of its last whorl. The threewhorls of which it consists have a yellowish marginatioii beneath the suture.122. Purpura armigera, Lamarck, 37,///. IX.123. Purpura bitubercularis, Lamarck, 37,///. IX.124. Purpura hippocastanum, Lamarck, 37,///. XI, XV.125. Purpura pica, Blainville, 37,///. IX.126. lopas situla. Reeve {Buccinum silula, Reeve, 37,11/.) IX.127. lopas sertum, Bruguiere (Buccinum sertum, Reeve, 37,111.) I.1 28. Sistrum digitatum, Lamarck (var. lobatum, Blainville ; Ricinula digitata, Reeve,37,111.) IX.129. Sistrum horridum, Lamarck {Eicinula horrida, Reeve, 37,///.) I, IX.130. Sistrum ricinus, Linn. (Nicimda arachnoides, Reeve, 37,111.) I, IX, XI, XV.131. Sistrum tuberculatum, Blainville (Ricinula tuberculata. Reeve, 37,111.) IX.132. Sistrum undatum, Chemnitz (Ricinula Jiscelhim, Reeve, 37, ///. Sistrum undatum,partim, Tryon, 41,//) VIII, X, XV.yellowish.133. Sistrum elatum, Blainville (Ricinula spectrum. Reeve, 37,111.) II, IX, XLIn the two fresh specimens obtained, the labrum is white, but the interior of the aperture is134. Sistrum spinosum, A. Adams (Ricimda chrysostoma, partim. Reeve, 37,111. Ricinulabiconica, partim, Tryon, 4:\,II.) XIII.Messrs H. and A. Adams (Genera Recent Mollusca, vol. i. p. 130) recognised that Reeve hadwrongly identified the Ricinula chrysostoma of Deshayes and imposed the name of spinosus uponthe misunderstood species. The term spinosus is applicable to fig. 12 6 rather than to 12 a, whichrepresents the Ricimda biconica of Blainville. I think therefore the species spinosus should berestricted to the figure 12 6. Whether it is conspecitic with S. biconicum has yet to be proved.Although united by Tryon, at present I am inclined to consider them sufficiently distinct.

610 EDGAB, A. SMITH.135. Sistrum biconicum, Blainville {Purpura biconiea, Kiener, 23. Sistrum biconicum,Tryon, ^\,II. Ricinula chrysosloma, partim, Reeve, 37,111.) XIII.136. Sistrum cavernosum, Reeve {Ricinula cavernosa, Reeve, 37,111.) IX, XV.137. Sistrum iostoma, A. Adams (PI. XXXV. fig. 14). {Murex iostonms, A. Adams,1, a.) VIII.This species is allied to S. spinosum, but appears to be separable.138. Sistrum squamosum, Pease, 31, a. XI.The Maldive specimen is quite typical.139. Sistrum concatenatum, Lamarck {Ricinula concatenata, Reeve, 37,111., va,r. = Purpurafragum, Blainville, 23). IX.A very variable species in size, form, and colour. Only a single small specimen was obtainedat the above station and it most resembles the variety fragum as the aperture and labrum arewhite and not orange red as in the type.140. Sistrum decussatum, Reeve, var. {Murex decussatus. Reeve, 37,111.) XIV.A single very small specimen differing from the type in having a shorter anterior canal, and inthe nodules at the upper angle of the whorls being uncoloured and acute. Although adult, only13 mm. in length.Family CORALLIOPHILIDAE.141. Coralliophila monodonta, Quoy and Gaimard {Pitrpura monodonta, 23). II, V, IX,XI, XIII.142. Coralliophila neritoidea, Gmelin {Purpu,ra violacea, Kiener, 37,111.) VIII, IX.143. Coralliophila suturalis, A. Adams, 1, b {C. galea (partim), 41, //. Rhizocheilus exaratus,Pease, 31, 6). IX, XV.144. Coralliophila squamosissima, Smith, 41,//. IX.145. Leptoconchus ellipticus, Sowerby {Magilus ellipticus, Sowerby, 40, «, XF///.) XV.The transverse ribbing usually extends over the greater part of the body-whorl, although, inthe description, Mr Sowerby observes that the shell is " spirally slightly ribbed below the middle,"as if this were a specific feature. ' A fine example in the British Museum from the Mauritius is27 mm. long, and 22 in diameter.146. Leptoconchus cumingii, Deshayes, 12, a, 4:0, a, XVIII. XV.The shell figured by Sowerby {I.e. fig. 10) as Magilus globulosus, I regard as a form of thepresent species.Family LOTORIIDAE.147. Lotorium chlorostoma, Lamarck {Triton chlorostonia, Reeve, 37,11.) IX, XV.148. Iiotorium gemmatum, Reeve {Triton gemmatum. Reeve, 37, //.) IX149. Lotorium pyrum, Lamarck {Triton pyrum. Reeve, 37, //.) IX.150. Lotorium tuberosum, Lamarck {Triton tuberosus. Reeve, 37, //.) I.151. Colubraria ceylonensis, Sowerby {Triton ceylonensis. Reeve, 37,//.) V, XIV.

MARINE MOLLUSCA. 611152. Colubraria obscura, Peeve {Triton ohsmrus, Reeve, 37,11.) XIV.153. Colubraria bracteata, Hinds {Triton bracteatus, Reeve, 37,//.) IX.A small form (Hilj' about 13 mm. in length.154. Colubraria digitale. Reeve {Triton digitate. Reeve, 37,11.) IX.In fresh specimens three rows of pale brownish spots are visible upon the last whorl, onebelow the suture, one at the middle, and the third below it. These spots form interrupted colourbands, which, however, are only observable in well preserved shells.1.5.5. Distortrix anus, Lamarck {Triton anus, Reeve, 37,11.) IX.156. Ranella bufonia, Lamarck, 37,11. IX, XV.157. Ranella granifera, Lamarck, 37, //. IX, XI, XIV.158. Ranella tuberosissima. Reeve, 37, //. XIV.159. Ranella thomae, d'Orbigny, 14 {R. bergeri, Canefri, 7). XII.The single Maldive specimen has the transverse ridges of a blackish brown colour but in otherrespects agrees very well with the examples cited from the above localities.160. Ranella (Lampas) lampas, Lamarck {Triton lampas, Reeve, 37,11.) IX.Family CASSIDIDAE.161. Cassis cornuta, Linn. 37, V. IX.162. Cassis rufa, Linn. 37, V. IX.Family DOLIIDAE.163. Malea pomum, Linn. {Doliitm pomimi. Reeve, 37, V.) IX.104. Dolium costatum, Menke, 37, V. IX.165. Dolium olearium, Lamarck, 37, V. XV.166. Pirula ficoides, Lamk. jun. ? 23 (Ficula reticulata, Reeve (non Lamarck), 37,111.)V, VII.Family CYPRAEIDAE.167. Cypraea arabica, Linn. {a. var. typica, 4:0, b, IV. IX. b. var. eglantina, Duclos,40, 6, /r. IX. c, var. histrio, Meuschen, 40, i, /!'. IX, XI, XII, XIII. d. var. intermedin. Gray,40,6,7F. IX.).168. Cypraea argus, Linn. 37,111. IX.169. Cypraea asellus, Linn. 37,///. IX,170. Cypraea caput-serpentis, Linn. 37,///. IX, XI, XV.171. Cypraea carneola, Linn. 37,111. I, IX, XI.172. Cypraea caurica, Linn. 37,111. IX, XI, XIII.

612 EDGAR A. SMITH.173. Cypraea clandestina, Linn. 37, ///. IX.174. Cypraea cribraria, Linn. 37,111. XIV.175. Cypraea erosa, Linn. 37,111. IX, XI, XIII, XV.176. Cypraea felina, Gmelin, var. 37,111. IX, XV.177. Cypraea gangrenosa, Solander, 40, 5, /r. X, XII.178. Cypraea (Epona) globulus, Linn. 37,111. XIII.179. Cypraea helvola, Linn. 37, ///. VIII, IX.180. Cypraea hirundo, Linn. 37, ///. IX, XIII.181. Cypraea Isabella, Linn. 37, ///. IX, XL182. Cypraea lamarckii, Gray, 37, ///. Ill, VIII.183. Cypraea lynx, Linn. 37,111. I, IX.184. Cypraea mauritiana, Linn. 37, ///. XL185. Cypraea minoridens, Melvill, 27, 6, 39, d {Cypraea fimhriata, partim, Sowerby,40, h,IV.) IX.186. Cypraea moneta, Linn. 37,111. IX, XI, XIII, XIV, XV.187. Cypraea poraria, Linn. 37,111. IX, XL188. Cypraea annulus, Linn. 37, ///. IX.189. Cypraea staphylaea, Linn. 37,111. VII.190. Cypraea talpa, Linn. 37,111. IX.191. Cypraea tigris, Linn. 37,111. IX.192. Cypraea vitellus, Linn. 37, ///. IX.193. Cypraea walkeri. Gray, 37,///. II, III, V, VI, XIIL194. Cypraea ziczac, Linn. 37,///. XIIL195. Trivia pellucidula, Gaskoin (Cypraea pellucidula, Sowerby, 40, 6, /F.) X.Family STROMBIDAE.196. Strombus dentatus, Linn. (var. Buppellii, Reeve, 37, VI.) I—VI.197. Strombus floridus, Lamk. 37, VI. I, IX, XI, XV.198. Strombus gibberulus, Linn. 37, VI. IX—XII, XIV, XV.199. Strombus labiosus. Gray, 37, VI. V, VI.200. Strombus lentiginosus, Linn. 37, VI. IX.201. Strombus guttatus (Chemnitz), Kiener, 23, 37, VI. V.202. Strombus lamarckii. Gray, 40, b, I. IX.

MARINE MOLLUSCA. 613203. Pterocera lambis, Linn. 37, VI. IX.204. Pterocera chiragra, Linn. 37, VI. IX.205. Terebellum terebellum, Linn. {Terebellum punctaium, Reeve, 37, VI.) II— VI, X.Family CERITHIIDAE.206. Triforis corrugatus. Hinds, 20, a, 8. X.207. Triforis elegans. Hinds, 20, a {T. jncturatus, Sowerl)y, 40, e). IX.I have compared the tyjje of T. picturatus with authentic specimens of the present speciesand have no hesitation in pronouncing them specifically the same. Although Mr Sowerby describedhis shell as having three keels on a whorl, there are in fact four, and they alternate, larger andsmaller, as stated by Hinds. No mention is made by either author of the spotted carina belowthe periphery of the body-whorl. Triforis is a genus wiiich wants monographing by a competentperson, and ought to be illustrated with much enlarged [ihotographed figures. At present it ispractically impossible to identifj' most of the described species by means of the published figuresand descriptions.208. Triforis sculptus. Hinds, 20, a. XIV.This species varies much in size, and is sometimes considerablj' larger than the shell figuredby Hinds or the dimensions given in his original description'. The largest specimen in the BritishMuseum is 20 mm. in length, whereas another, equally adult, is only 1-5.209. Triforis lilaceocinctus, n. sp. (PI. XXXV. fig. 1.5). XIV.Testa elongato-pupoidea, supra acuminata, granulis flavescentibus et albis, lirata, inter granularufo punctata; anfractus circiter L5, superiores liris duabus granosis aequalibus instructi, paucianteriores lira graciliore mediana, dilute lilacea, vix granulata ornata, sutura lineari sejuncti, microscopicespiraliter striati, ultimus circa basim lilaceus, liris aliis tribus nodulosis, rufo punctatis,instructus ; apertura obliqua, piriformis ; canalis parvus, dextrorsus, semiclausus.Longit. 10|^ mm., diam. 3^ mm.A general glance at this pretty species gives the impression that the whorls have each twoadjacent rows of large granules. Such however is not the case. It is the lower row in one whorlbeing adjacent to the upper one in another (the linear suture being between) that gives thisappearance, the unspotted and more slender median lirae also lending to the effect. This liragradually dies out as it ascends the spire, so that the upper whorls have only two rows of equalsized granules. This species also occurs at the Mauritius (Brit. Mu.s.).210. Triforis excellens, n. sp. (PI. XXXV. figs. 16, 17). V.Testa magna, dilute fuscescens, hie illic saturatius maculata; anfractus numerosi (2.5— 30), plani,cingulis tribus aequalibus acutis cincti, inter cingula laeves, ultimus ad peripheriam bicingulatus,infra vix convexus, liris 4—5 instructus ; apertura irregulariter quadrata ; labrum teuue ; columellacallo reflexo crassiusculo induta.Longit. 29 ram., diam. 6 mm.The spirals are equal in size, but the space separating the lowermost from the median oneis a little broader than the groove between the upper two. The suture except at the upper partof the spire is marked with a spiral thread.' Ann. Mtifi. Nat. Hist. 1843, vol. xi. p. 17.G. II. 79

614 EDGAR A. SMITH.211. Triforis gracilior, n. sp. (PL XXXV. figs. 18, 19). V.Testa T. excellenti similis, sed gracilior, cingulis duobus inferioribus subundulatis, alba, hie illicfusco maculata.Longit. 28 mm., diam. 5| mm.Like T. excellens, this species has three keels upon each whorl, but they are not so equal,the uppermost being a trifle more slender than the others. The latter also are slightly affectedby faint longitudinal depressions giving them an obscurely beaded appearance. The body-whorl isbicarinate at the periphery and has three or four lirae beneath. As in the preceding species, thespace between the second and third keel is a little broader than that which separates the firstand second, and the suture is filo-lirate.212. Triforis pura, n. sp. (PI. XXXV. figs. 20, 21). XII.Testa elongata, alba, clathrata, granulata ; anfractus circiter 20, fere plani, costis spiralibustribus granosis inaequalibus (costa mediana minima) cincti, inter costas longitudinaliter costati,ultimus costis senis (prope labrum duabus intercalatis) ornatus ; canalis dextrorsus, clausus, laevisapertura irregulariter ovata, obliqua ; labrum antice prominens, postice recedens ; columella callocrassiusculo reflexo induta.Longit. 14 mm., diam. 3.Of the three spirals the uppermost is a little stouter than the lowermost and the central oneis rather finer than the latter. The granules form oblique rows of three, being connected by thelongitudinal costae. The suture is thread-like.213. Vertagus fasciatus, Bruguiere, var. 4:0, a, XV. VIII, IX.214. Vertagus kochi, Philippi, 40, a, XT. XL215. Vertagus articulatus, A. Adams and Reeve (Cerithium articulatum. Adams and Reeve,3. V. articulatus, Sowerby, 40, a, A'F.) VI, X.216. Vertagus obeliscus, Bruguiere, var. cedo-nuUi (F. cedo-nulli, Sowerby, 40, a, A'F.)I, IX.V. cedo-nuUi is perhaps separable from oheliscus.217. Cerithium columna, Sowerby, 40,

MARINE MOLLUSCA. 615Family PLANAXIDAE.226. Planaxis ineptus, Gould, 17, 40, a, XX, 41, /A'. X.The Maldive specimens are a little larger than the dimensions given by Gould, being 5| mm.in length. Most of them also exhibit a purplish stain on the columella which is not referred toin the original description. There are generally three principal colour lines upon the body-whorl—one above the periphery, one below it and the third still more anterior.Family LITTORINIDAE.227. Littorina glabrata, Piiilippi, 33,6, 37, X. XI, XV.228. Littorina scabra, Linn. 37, X. XV.229. Littorina undulata, Gray, 37, X. XI, XV.Family SOLARIIDAE.230. Solarium modestum, Philippi, 40, b, I. V.231. Philippia cingulum, Kiener, 4:0, b, III. II, IX.Family HIPPONYCIDAE.232. Mitrularia cicatricosa. Reeve ifialyftraea cicatricosd, Reeve, 37, XI.) IX.233. Mitrularia equestris, Liun, {Calyptraea equestris, Reeve, 37, X/.) IX.234. Hipponyx danieli, Crosse {Cajndus danieli, Crosse, 11, b). Ill—V.235. Hipponyx australis, Lamarck, 41, VIII.Family CAPULIDAE.236. Thyca crystallina, Gould {Hipponyx crystcdlinus, Tryon, 41, VIII.) VIII.Family XENOPHORIDAE.237. Xenophora indica, Gmelin, 41,1'///. (Phorus indica, Reeve, 37,/.) V.Family VANICOROIDAE.238. Vanicoro cancellata, Lamarck, 41, VIII., 40, b, V. IX, XIII.Family NATICIDAE.239. Natica robillardi, Sowerby, 40, d. XII, XV.240. Natica euzona, Recluz (PI. XXXV. fig. 22), 36 (iV. picta, partim, Reeve, 37, /A'.N. decora, Philippi, 33, a). VII.The operculum of this species is shelly, white, concave externally, shining except in the middlewhere there is a dull opaque thickening. The outer curved side has a tiiickened edge, within79—2

616 EDUAK. A. SMITH.which is a parallel furrow and then a raised ridge or rounded keel. The convex side is coveredwith a thin yellow pellicle and is marked with lines of growth.241. Polinices mamilla, Lamarck {Natica mamiUa, Reeve, 37, IX.) Ill, IX, XTI, XV.242. Polinices albumen, Lamarck {Natica albumen. Reeve, 37, IX.) III.243. Mamilla melanostoma, Lamarck {Natica melanostoma, Reeve, 37, IX.) VI, XV.244. Mamilla simiae, Deshayes {Natica simiae, Reeve, 37, IX.) IX.Family lANTHINIDAE.245. lanthina communis, Lamarck? 37, XI. IX.The figures most resembling the specimens from the above station are Reeve's figures of/. affinis (figs. 2 a, b). That so-called species and several others described in the same monographare probably mere varieties of one variable species. (See Tryon, Maî. Conch, vol. ix. pp. 36, 37.)Family SOALIDAE.246. Scala replicata, Sowerby {Scalaria replicata, Sowerby, 40,6,7.) IX.247. Scala censors, Crosse and Fischer {Scalaria consors, Tryon, 41, IX.) XI.A single example considerably larger than the type, being 18 mm. long, and 7 mm. in width.The locality given by Crosse and Fischer is St Vincent's Gulf, S. Australia, but four specimens,supposed to include the type among them, were presented to the British Museum in 1870 byMr G. F. Angas and were marked "Ceylon" by him. The Maldive example has a dark line atthe suture.248. Scala (Cirsotrema) texta, n. sp. (PI. XXXV. fig. 23). X.Testa elongata, subulata, imperforata, solidiuscula, albida, longitudinaliter plus minus plicata,varicibus paucis obliquis instructa, spiraliter sulcata et tenuiter punctato-striata, lineis incrementitenuissimis obliquis sculpta ; anfractus circiter 12, supra valde declives, vix concavi, in medio obtuseangulati, sutura obliqua irregulariter corrugata sejuncti, ultimus ad peripheriam angulatus, costis adangulos subnodosis; apertura oblique ovata ;peristoma continuum, expansum, margine externo varicecrasso circumdato. Longit. 17 mm., diam. 5; apertura intus 3 longa, 2 lata.This very distinct species is well-characterized by the fine cancellated sculpture, like a pieceof linen, the interstices being minutely punctate. The whorls exhibit spiral shallow sulci andintervening raised ridges, both the latter and the grooves being covered with the spiral and longitudinalstriae. Every second or third whorl exhibits an oblique varix, and the upper ends of theplicae form a very irregular puckered or dentate sutural line.spirallyAllied to S. bicarinata, Sowerby, but much larger, of different form, differently plicate andsulcate.Family PYRAMIDELLIDAE.249. Pyramidella corrugata, Lamarck, 23. XV.2.50. Pyramidella nodicincta, A. Adams, 40, b, II. XIV.251. Obeliscus dolabratus, Linn. {0. dolabratus and 0. terebelhrni,' ^0,b, II.) IX, XV.

252. Obeliscus monilis, A. Adams, 40,/;,//. IX, XIV.253. Obeliscus sulcatus, A. Adams, 40,?;,//. XV.MARINE MOLLUSCA. 617Family NERITIDAE.254. Nerita albicilla, Linn. 37, IX. IX, XV.255. Nerita histrio, Linn. 37, IX. XI.256. Nerita plicata, Linn. 37, IX. IX, XL257. Nerita polita, Linn. 37, IX. I, XII.Family TURBINIDAE.IX,258. Turbo (Senectus) argyrostoma, Linn. 37, IV. (var. = T. margaritaceus, Eeeve, 37, IV.)XI, XV.Family LIOTTIDAE.259. Liotia squamicostata, n. sp. (PI. XXXV. fig. 24). X.Testa subglobosa, anguste umbilicata, alba ; anfractus quatuor, ad suturam canaliculati, costisgranosis spiralibus (in anfractu penultimo 4, in ultimo 8) cincti ;granula ad peripheriam subsquamiformia; apertura circularis, margine externo crenulo, columellari incrassato, reflexo. Diam. maj.5 mm., alt. 4.The spiral ridges are rather strong, broader than the grooves between them, and the granulesupon the second, third, fourth, and lifth upon the body-whorl, and the second and third upon thepenultimate, are scale-like, and that which encircles the umbilicus is much thicker than the rest andtransversely grooved. The terminations of the spirals upon the outer lip give it a crenulated aspect.Family TROCHIDAE.260. Trochus (Lamprostoma) incrassatus, Lamarck, 34, XI. I, XV.261. Trochus (Lamprostoma) maculatus, Linn. 34, A'/. IX, XL262. Trochus (Lamprostoma) obesus, Reeve, 37, XIII. IX.263. Trochus (Lamprostoma) radiatus, Gmehn, 34, XI. XL264. Thalotia maldivensis, n. sp. (PI. XXXV. figs. 25, 26). II, X.Testa parva, elate conica, imperforata, ad peripheriam acute angulata, supra viridis, ad suturamalbo et roseo maculata, apicem versus rubescens, supra anfi-actum ultimum strigis albis obliquis paucisornata, infra roseo et albo tessellata ; anfractus 8—9 plani, seriebus granulorum parvorum septenis(quarum series duae inferiores contiguae et albo et roseo maculatae) instructi, ultimus infra angulumseriebus 9— 10 ornatus, subplanus ; apertura obliqua, subquadrata, margaritacea, iridescens; labrumtenue ; columella alba, incrassata, reflexa, leviter arcuata, antice truncata.Diam. maj. 7|^ mm., min. 7, alt. 10. Var. Testa rufescens, concolor.A very pretty conical shell, generally more or less green with a white and pink spotted bandabove the suture and dotted with pink in the middle of the base. Some examples are uniformlypinkish reddish and with only tinges of green above or below.

. 270.618 EDGAE A. SMITH.265. Clanculus atropurpureus, Gould [Trochus (Clanculus) atropurpureus, 3^, XI.) IX, XIII.266. Perrinia angiilifera, A. Adams (PI. XXXV. fig. 27) ;{Turcica (Perrinia) angulifera,34, XI). X.267. Forskalia pulcherrima, A. Adams {Gibbula pukherrima, Pilsbry, 34, XI.) IV, VI.268. Monilea calyculus, Wood, 34, X7. II—IV.269. Monilia simulans. Smith, var. 39, c. V, VI, X.These specimens differ from the type in having only very faint indications of the nodoseplications at the upper angle of the whorls. They also differ in colour, being paler and less rosy.Trochus {Monilea) warnefordi, G. and H. Nevill, may be the same as this species.Ethalia rhodomphala, n. sp. (PL XXXVI. figs. 1, 2). Ill, V, X.Testa orbiculata, supra breviter conica, semiobtecte anguste umbilicata, ad peripheriam acuteangulata, supra albida, maculis paucis remotis fuscis et lineis tenuissimis irregularibus undulatisradiatim picta, ad peripheriam maculis semipellucidis roseo pictis ornata, infra lineis albis opacisirregularibus subziffzagformibus variesata, circa umbilicum rosea ; anfractus sex leves, nitidi, ultimuscirca medium striis paucis sculptus, circa umbilicum radiatim plicatus ; apertura oblique subquadrata,margaritacea, iridescens ; columella crassa, in medio margaritacea, valde reflexa, alba vel rosea, callosa,umbilicum semiobtegens.Diam. maj. 8 mm., min. 7, alt. 3|.Viewed with the naked eye, the upper surface of this shell looks whitish with a few brownradiating blotches. A closer inspection with a lens, however, reveals the presence of very tinelineation, more or less broken up, undulating or dotted. The puckering around the umbilicus ispinkish, the rest of the base being covered with opaque white irregular markings upon a subtranslucentground. The last whorl is angled at the periphery and above the angle is markedwith a few distinct spiral striae.Family STOMATELLIDAE.271. Gena auricula, Lamarck, 34, XIL IX, XIII.Family HALIOTIDAE.272. Haliotis ovina, Chemnitz, 34, XII. IX, XII.The number of open perforations may vary from two to six.Family FISSURELLIDAE.273. Glyphis bombayana, Sowerby, 34, XII. IX.274. Glyphis singaporensis. Reeve, 34, XII. XIII.275. Emarginula incisura, A. Adams, 34, XII. XIII.The locality of this species has not previously been recorded. The single specimen obtainedis of a greenish yellow tint externally and the central portion of the interior is of a somewhatsimilar colour. The anterior slit is verj"- peculiar, being clean-cut, and extending from the marginalmost to the apex.

276. Emarginula planulata, A. Adams, 34, XII. VIII.A single specimen apparently inseparable from this species.MARINE MOLLUSCA. 619Family CHITONIDAE.277. Chiton (Sclerochiton) miles, Carpenter, 34, X/r. I.Torres Straits is the only locality previously known for this Chiton.278. Schizochiton incisus, Sowerby, 34, X/T. I.This I believe is the tirst record of the occurrence of this remarkable species in the Indian Ocean.Family ISCHNOCHITONIDAE.279. Callochiton platessa, Gould, 34, XIV. V.280. Ischnochiton hululensis, n. sp. (PI. XXXVI. figs. 3—6). IX.Testa ovata, mediocriter elata, roseo-albida, punctis roseo-griseis numerosis ornata, cingulo minutesquaniulato, albido viridi-griseo maculato, circumdata ; valvae undique minute decussatae, anticatransversim corrugata, lamina inserta brevi, fissuris novem instructa, medianae areis lateralibus benecircumscriptis, elatis, transversim corrugatis, postica mucrone centrali instructa, dimidio posterioriconvexo, anteriore concavo et corrugato, lamina inserta fissuris undecim parata ; squamae cinguliminutae, acute ovales, transversim striatae.Longit. 13 mm., diam. 19.The single specimen obtained is of a pale pinkish colour down the sides of the valves andwhitish flecked and spotted with greenish grey down the middle. The hinder almost straight edgeof the valves is pale with a few greenish grey spots and a dash of the same colour occurs alongthe sides in front of the lateral areas. The girdle is covered with alternate patches of greyishgreen and white scales. The insertion-plates of median valves have a single slit, that of the frontvalve has nine slits and that of the tail-valve eleven.281. Ischnochiton feliduensis, n. sp. (PI. XXXVI. figs. 11—14). VII.Testa ovata, mediocriter elata, in medio carinata, pallida, sordide alba; valvae tenuissimae,antica et areae laterales valvarum centralium minute granulatae ; areae centrales longitudinalitergrano-liratae ; valva anterior semicircularis, postice in medio sinuata ; mucro valvae posterioris antemedianus,parum prominens; cingulum album, squamis miuutis striatis ornatum. Longit. 6 mm.,diam.4 mm.Remarkable for the thinness of the valves, the flatness of the lateral areas, and its style ofsculpture. The posterior valve has twelve slits in the insertion plate, the anterior has nine andthe intermediate valves one.282. Ischnochiton maldivensis, n. sp. (PI. XXXVI. tigs. 7—10). VII.Testa elongato-ovata, elata, convexa, in medio subcarinata, pallida, plus minus rufescens, albominute punctata, cingulo minute squamulato griseo maculato circumdata ; valva antica et areaelaterales laeves, areae centrales sulcis paucis longitudinalibus utrinque sculptis, valva posterior inmedio mucronata ; squamae cinguli minutae, adamantiformes, indistincte striatae.Longit. 8 mm., diam. 4.The salient features of this species are the smoothness of the head-valve and the lateral areas,and the distinct incised lines upon the sides of the central areas, a space down the middle of

620 EDGAR A. SMITH.the shell being smooth. The insertion plates are thick and striated across the edge. The anteriorvalve exhibits eight slits, the posterior ten and the median valves none.Family ACANTHOCHITIDAE.283. Acanthochites (Loboplax) laqueatus, Sowerby, 34, A'/ F. {Angada teirica, 34, Z/T.)V, XII, XIV.Testa parva, elongata, subdepressa, purpureo-rosea, albo variegata, valvis antica et posticapallidis, cingulo puniceo vel viridi, hie illic albo maculato, circumdata ; valvae rugose squamataeantica costis radiantibus quinque vix elatis instructa, undique squamata, medianae angustae, inmedio postice rostratae, area dorsali sublaevi, postica undique squamata, breviter mucronata.Longit. 16 mm., diam. 12 mm.This species is remarkable for its brilliant variable colour, the narrowness of the central valvesand theircoarse squamulation.The anterior valve in the Maldive specimens is greenish grey with five paler rays and theposterior margins are also whitish with one or two black spots. Central valves purplish rose withsome whitish streaks or wrinkles on each side the dorsal area. Mantle purple red with a whitespot on eacli side the first, seventh and eighth valves surrounding the lateral pores there situated,also some black spots set in white rings all round the edge, about 17 or 18 altogether, and witha fringe at the extreme margin of short white spicules.Another specimen has the valves similarly coloured, only the seventh is decidedly greenexcepting the rosy-purplish dorsal area. The mantle, however, is of a vivid green, witli a whitestripe on each side the anterior valve and four or five stripes or spots in front, the outer marginwith a similar fringe of spicules.Valves. First valve semicircular, the posterior margins being slightly divergent, exhibiting fivenot much raised rays which, like the rest of the surface, are covered with coarse elongate scaleswhich are finer towards the middle of the hinder edge. Insertion plate finely striated externally,acute at the edge, with five shallow slits.Central valves narrow, curved in front and rather acutely beaked behind ; dorsal area narrow,smooth, with cross marks of growth ; squamae arranged in rows, some parallel with the posteriormargin, others obliquely across the valves, three or four rows on each side the dorsal area beingwhite; insertion plates with a single posterior slit.Posterior valve semicircular, shortly mucronate, squamate everywhere, except upon the shortmucro which of course is like the dorsal area of the preceding valve ; insertion plate thickish,withnine slits.The colour of the interior of the valves of the only specimens disarticulated is a pinkish fieshtint, the head and tail valves being -paler than the rest.It does not seem to me advisable to place this species in the genus Angasia as distinct fromAcanthochites. I might also point out that the name Angasia was preoccupied in Crustacea. (SeeP. Z. S. 1863.)FamilyCRYPTOPLACIDAE.28i. Cryptoplax burrowi, Smith, 34, ZT. IX.

auriculaMARINE MOLLUSCA. 621FamilyNEOMENIIDAE.285. Proneomenia australis, Thiele, 3^, XVII. V.Only a single specimen, apparently belonging to this species, was obtained.FamilySPONDYLIDAE.286. Spondylus imperialis, Clienu, 37, /Z. IV.FamilyLIMIDAE.287. Lima (Mantellum) ft-agilis, Chemnitz, 40, h, I. I, IX, XI, XV.288. Iiima (Mantellum) inflata, Cliemnitz, 4:0, b, I. (Lima faaciata, 40, i,/.) XIII.289. Lima squamosa, Lamarck, 40, b, 7. II.290. Lima (Ptenoides) tenera, Chemnitz jun. ? 40, b, I. V.Family PECTINIDAE.291. Pecten senatorius, Gmelin, 40,6,/., 37, Fill. II—VI.Only young specimens obtained. P. layardi, Reeve, P. crisitdarin, Adams and Reeve, P. rugosus,Sowerby and some other so-called species, I regard as half-grown or young specimens of thepresentform.292. Pecten lemniscatus. Reeve, var. 37, VIII. II.293. Pecten mirificus. Reeve, 37, VIII. V.294. Pecten noduliferus, Sowerby, 40, b, 7. V, XII.295. Pecten irregularis, Sowerby, 40 6,7., 15. V, X, XII.Remarkable for the very numerous tine costae which are closely prickly scaled in fresh youngspecimens.296. Pecten nux, Reeve, 37, 17/7. II, V, VI.297. Pecten cooperi, n. sp. (PI. XXXVI. figs. 15—18). VII.Testa parva, compressa, albida, rufo maculata, aequivalvis ; valva sinistra costis principalibusnovem et aliis gracilioribus intercalatis instructa, supra costas pulcherrime concentrice lamellataauriculae valde inaequales, postica minima, antica costis 2—3 magnis aliisque paucis tenuibus ornata,transversim tenuiter lamellata, lamellis supra costas incrassatis, conspicuis ; valva dextra costiscirciter 12, tri- vel quadripartitis, instructa, concentrice tenuiter lamellata ;tenuibus radiantibus circiter 10 squamulatis ornata, costa suprema marginali ma.xima.antica costisLongit. 12^ mm., alt. 14^, diam. 4.A single example only was obtained. The species has very remarkable sculpture and %'eryunequal auricles. The concentric lamellae are similar on both valves Ijut the costae are different.On the left valve there are about nine principal ones with a secondary one between them andoften with still finer ones on each side of the secondaries. The right valve has about twelve costaeeach made up of three to five small ones, or in other words it is ornamented with numerousG. II. 80

622 EDGAE A. SMITH.slender riblets arranged in groups of three to five. Named after Mr Forster Cooper who wasassociated with jNIr Stanley Gardiner in the exploration of these islands.298. Pecten maldivensis, n. sp. (PI. XXXVI. figs. 19, 20). II, IV, VI.Testa compressissima, albida, plus minus roseo radiata et maculata, et maculis albis opacisinterdum variegata, tenuissime radiatim striata, lineisque incrementi tenuibus sculpta ; valvae subaequales,dextra vix convexiore ; auriculae inaequales, posticis paulo majoribus, levibus, anticis cpstistenuissimis paucis radiantibus ornatis.Longit. 17 mm., alt. 19, diam. 3^.Very compressed and usually very finely radiately striated, but sometimes smoother, with lessdistinct striae. The colour is variable, some specimens are entirely white with only a few colourspotson the dorsal slopes. Others are dirty whitish, with about seven rather obscure reddish raysand one example has the right valve rayed with red and the left blotched with opaque white andred. All exhibit the red-spotting at the sides of the dorsal slopes.299. Janira gardineri, n. sp. (PI. XXXVI. figs. 21, 22). V, VII.Testa mediocriter compressa, suborbicularis, costis 19 planatis, quadratis, latioribus quam sulci,instructa, undique confertim tenuissime concentrice lamellata ,• valva sinistra plana, albida, rufolineata et punctata, dextra alba, umbones versus rufo tincta ; umbones laeves, acuti, contigui, baudradiatim striati, nitidi, albidi, lateribus convergentibus rectis ; auriculae inaequales, posticis paulomajoribus, costis paucis radiantibus tenuibus parum conspicuis instructae, transversim tenuissimelamellatae, et linea cardinis valvae dextra squamicristata ;pagina interna alba.Longit. 25 mm., alt. 23, diain. 6.A ver)' beautiful species well characterized by the flat^topped and square-cut costae which arerather broader than the intervening grooves. The concentric fine lamellae seem liable to disappearfrom the grooves in the flat valve, but they are very conspicuous on the costae and towards theumbo are thickened, so that they are more like granules than lamellae. The red markings occurboth on and between the ribs. In the convex valve the lamellae are as conspicuous in tlie sulcias upon the costae. The lamellae upon tlie auricles are much more delicate and closer than thoseupon the rest of the shell. This species probably attains larger dimensions tlian those given above.300. Pallium plica, Linn. [Pecten plica : Reeve, 37, VJII). II— VI.301. Amussium paucilirata, n. sp. (PI. XXXVI. figs. 23, 24). V.Testa parva, compressa, tenuis, pellucida, laevis, polita, aequivalvis, valva sinistra alba, dextrapellucida albo et rufo radiata et variegata, radio conspicuo albo supra latus anticum ornata; auriculaeinaequales, postica valvae sinistrae infra leviter sinuata, posteriori valvae dextrae majori ; umbonesacuti;pagina interna radiatim substriata, lira brevi unica utrinque insti'ucta.Longit. 7^ mm., alt. 7J,diam. 2.An interesting little species, having one valve pure white and the other mottled and rayedwitli white and red. The presence of only two internal lirae is also remarkable. In addition tothese a short lira runs from the ligament-pit along the base of each auricle. Although tliesurface of both valves looks smooth and glossy, under a lens fine striae of growth are visible.The umbones are acute, that in the coloured or right valve being a little more prominent thanthat of the left. The opaque white ray down the anterior side appears to be a specific feature,for it is present in all the specimens examined.302. Semipecten forbesianus, Adams and Reeve, 37, VJ.

MARINE MOLLUSCA. 623FamilyPTERIIDAE.303. Malleus anatinus, Gmelin, 37, XI. IV.304. Vulsella rugosa, Lamarck, 13. XII.30.3. Electroma ala-corvi, Chemnitz {Avicula ala-corvi, Reeve, 37, X) XV.306. Electroma zebra, Reeve {Avicula zebra, Reeve, 37, X) X.307. Melina perna, Linn. {Ostrea jKnia, Hanley, 19,6. Pi-nia, {Isognomon) samoensis, Baird,,5.) XL308. Pinna muricata (Linn.), Reeve, 37, XL XV.309. Pinna nigra (Chemnitz), Dillwyn, 37, XI. IX.310. Pinna saccata, Linn. 37, A'/. I.311. Pinna serrata, Solander (jun. ?), 37, XI. VII.FamilyMYTILIDAE.312. Modiola arborescens, Chemnitz, 37, X IX, X, XIII, XIV.313. Modiola auriculata, Krau.ss, 25, 10. IX.3U. Modiola flavida, Dunker, 37, A'. X.315. Lithodomus cinnamominus, Chemnitz, 37, A'. II.316. Iiithodomus gracilis, Philippi, 37, X. XII.317. Lithodomus malaccanus. Reeve (Young?), 37, A'. IX.318. Lithodomus nasutus, Philippi var. ? 37, A'. XIV.319. Lithodomus teres, Philippi? 37, X. VII, XV.320. Modiolaria argentea. Reeve (Lithodomus argenteus, Reeve, 37, X) II.321. Septifer bilocularis, Linn. (MytUus nicobaricus, Reeve, 37, X.) XII.FamilyARCIDAE.322. Area maculata, Sowerby, 37,//. I, IX, XI, XV.323. Area imbricata, Bruguiere, 37, //. IX, XV.324. Area (Anadara) elathrata. Reeve, 37,11. VII.325. Area (Anadara) urypygmelana, Bory, 37,11. VII, IX.326. Area (Anadara) antiquata, Linn. 37, //. Maldives.327. Area (Seapharea) rhombea. Born, 37,//. IX.328. Area (Aear) symmetrica. Reeve, 37,11. VII, VIII.329. Area (Aear) domingensis, Lamarck, 24. II. VIL IX, XIII, XIV.80—2

624 EDGAR A. SMITH.330. Area (Barbatia) lacerata, Linn. 37,11. II.331. Area (Barbatia) lima, Reeve, 37,//. II, V, IX, XIV, XV.332. Area (Barbatia) tenella, Reeve, 37,//. I, IX, XV.FamUy CARDITIDAE.333. Mytilieardia variegata, Bruguiere {Cardita variegata. Reeve, 37, /.) I, IX, XI, XV.Family GALEOMMIDAE.334. Galeomma formosa, Deshayes, 4:0, b, III. XIV.335. Thyreopsis coralliophila, H. Adams, 2. II.In this remarkable genus the mantle is united ventrally, with a small anterior slit for thepassage of a small pointed foot, and a very minute anal opening behind, near to which thesurface is somewhat scabrous or minutely papillose. There is a narrow free fold of the mantlebordering the margin of the valves which are thickened within and gives rise to a delicate ribletwhich extends across the inner surface of each valve from a point near the middle about halfway towards the umbo^. Only faint traces of adductor scars are visible and probably the freeedge of the mantle above referred to is the principal means of attachment to the shell. It doesnot appear as if it would be reflected upon the exterior of the shell when living. In a formwhere the valves are permanently more or less spread out almost horizontally, the animal beingtoo large for them to close, adductor muscles would be of little service, and therefore we mightexpect to find them but feebly developed. The shell is of a purplish tint within and without,except towards one end, which is white. The exterior is excessively finely concentrically striateand microscopically radiately striate and the inner surface of the valves appears to be minutelypitted. The dorsal margins are thickened within and the ligament is attached in a depression ofthis thickening immediately beneath the minute, glossy, convex, boss-like umbones.Family TRIDACNIDAE.336. Tridaena eumingii, Reeve, 37, XIV. IX.Family CARDIIDAE.337. Cardium leucostoma. Born, 37, //. IX.338. Cardium nebulosum. Reeve, 37, //. II.339. Cardium maculosum. Wood, 37,//. III.340. Cardium levisuleatum, n, sp. (PL XXXVI. figs. 2.5, 26). IX.Testa irregulariter quadrata, inaequilateralis, alba, mediocriter convexa, latere autico brevi,rotundato, postico oblique curvatim truncato, multo majori, margine ventrali late arcuato ; valvaeradiatim anguste sulcatae quam costis multo angustiores ; costae planiusculae, ciroiter 25, quarum' This riblet is only feebly indicated in Adams's type iu the British Museum by a slight sinuatiou of themargin at that point.

MARINE MOLLUSCA. 625anteriores squamis transversis subgrauuliformibus subconfeitis instructae, posteriores haud granulataesed transversim tenuissime striatae.Longit. 15 mm., alt. 12, diam. 8i.Remarkable for its somewhat compressed and quadrate form, the slender radiating sulci andthe slightly raised ribs, of which only the anterior half bear transverse granules, those on thehinder half of the shell being only very finely transversely striated. The colour is entirely whiteexcepting the dorsal margin just in front of the umbones, which is stained with pink.341. Cardium sueziense, Issel, 21, 39, a. II, X, XV.342. Cardium (Laevicardium) lobulatum, Deshayes, 12, c. II, III, V, VII.343. Cardium (Laevicardium) australe, Sowerbj', 37,//. TX, XII, XIII, XV.344. Cardium (Laevicardium) biradiatum, Bruguiere, 37, //. V, VII, IX, XII.34-5. Cardium (Ctenocardia) victor, Angas, 4. VIII.The ribs on the greater part of this beautiful shell are alternately larger and smaller, theformer being spinosely squamate and the latter only very delicately scaled. On the posterior endthe costae are about equal in stoutness and ornamented with short scale-like spines.346. Cardium (Ctenocardia) fornicatum, Sowerby, 37, //. V, X.FamilyCHAMIDAE.347. Chama jukesi. Reeve, 37, /T. I.348. Chama imbricata, Broderip, 37, IV. IX.FamilyCYPRINIDAE.349. Meiocardia lamarckii. Reeve, 37, //. V.350. Trapezium oblongum, Linn. 37,/. V.FamilyVENERIDAE.351. Venus reticulata, Linn. 37, Z/F. I, IX.352. Venus marica, Linn. 37, XIV. IX, XV.353. Venus recognita, Smith, 39, a. II.

626 EDGAR A. SMITH.FamilyPETRICOLIDAE.358. Petricola lapicida, Chemnitz, 40, «, X/X II, VIII, XV.FamilyPSAMMOBIIDAE.359. Psammobia rugulosa, Adams and Reeve, 37, X. X.360. Psammobia pulcherrima, Deshayes, 37, A', 39, a. X.The Maldive .specimen is considerably larger than the type described by Deshayes, being31 millim. long, and 16 broad. It is whitish with several irregular somewhat broken purple redrays which are also visible upon the inner surface of the valves. The scales upon the posteriorcostae become obsolete as the shell increases.361. Asaphis deflorata, Linn. {Capsa deflorata, Reeve, 37, X). IX.Family ROCELLARIIDAE.362. Rocellaria gigantea, Deshayes (Gastrochaena gigantea, Sowerby, 190, «, JTX). IX.363. Rocellaria mytiloides, Lamarck {Gastrochaena mytiloides, Sowerby, 37, XX). XII.Family MESODESMATIDAE.364. Paphia trigona, Deshayes (Mesodesma trigona, Reeve, 37, VIII). IX.365. Paphia glabrata, Gmelin (Mesodesma glabrata, Reeve, 37, VIII). IX.Family LUCINIDAE.366. Lucina (Codakia) divergens, Philippi, 33, b. {Lucina fibida, Reeve, 37, VI). IX.367. Lucina (Codakia) punctata, Linn. 37, VI. IX.368. Lucina (Divaricella) dalliana, Vanatta var. 42. IX.Three valves from the Maldives are a trifle more globose than S. African specimens, thedivaricating lines are rather less numerous, and the smooth band, where they meet, is not quiteso evident. In typical and especially in young examples the posterior straight dorsal margin formsa rounded angle where it meets the posterior curved outline. This angle is less apparent in theHululespecimens.The very fine crenulation within the margin of the valves is similar in both forms.This species has been erroneously quoted by Mr Sowerby as L. quadnsulcata, d'Orbigny,(Marine Shells S. Afi-ica, Appendix, p. 26). Of this I speak with certainty as the shells so-namedby him are now in the British Museum.369. Cryptodon globosus, Forskal (Lucina globosa, Pfeififer, 32). IX.FamilyTELLINIDAE.370. Tellina elegans. Gray, Ô, a, XVII. IX.371. Tellina crucigera, Lamarck, var. amoena, Deshayes, 37, AT//. IX.

372. Tellina rastellum, Hanley, 19. XV.373. Tellina dispar, Conrad, 40,6,/. IX.MARINE MOLLUSCA. 627Two specimens, one white .suffused with pale yellow, the other e.xhibiting a broad rosy rayposteriorly and a fainter one in front.374. Tellina rhomboides, Quoy and Gaimard, 19, a. XV.375. Tellina robusta, Hanley, 19, n. X, XIV, XV.376. Tellina rugosa, Bom, Ô, a, XVII. IX.377. Tellina scobinata, Linn. 40, a, XVII. IX.378. Tellina carnicolor, Hanley, 40, i, 7 {Tellina corhis, Sowerby, 40,6,7. Tellina strangei,Deshayes, 12, c.) Ill, X.The types of T. corhis and T. strangei being in the British Museum collection I have carefullycompared them with Hanley's species and I fail to discern even varietal differences. The "moreequilateral" form in T. corhis spoken of by Sowerby is so very slight as to be scarcely appreciableand may be regarded merely as an individual variation. Tellina iessellaia, Deshayes from MoretonBay {= T. tenuistriata, Sowerby, Con. Icon. fig. 128) is also closely allied but is somewhat diflerentlysculptured. T. tenuistriata is described as " orange " in colour, but the figure is purplishbrown in the copy of the work at hand. In reality it ia of a pale fleshy tint and orange alongthe dorsal margins, with some opaque white markings radiating from the umbones.379. Tellina verrucosa, Hanley, 40, «, A'777. IV.Family SCROBICULARIIDAE.380. Semele jukesi, A. Adams {Ampliidesma jukesii. Reeve, 37, VIII). VIII.Family CUSPIDARIIDAE.381. Cuspidaria elegans. Hinds (Neaera elegans, Smith, 39, a; Neaera moluccana, Adamsand Reeve, 3). X.LITERATURE.1. Adams, A. (a) Proc. Zool. Sue, 18.51, pji. 267 et seq.; (b) Proc. Zuul. Soc, 18.53,pp. 69—74, 94—99, 116—119; (c) Thes. Conch., Vol. ii.2. Adams, H. Proc. Zool. Soc, 1868, pp. 12—17, 288—294.3. Adams and Reeve. Voi/age " Sumarang."4. Angas. Proc. Zool. Soc, 1872, pp. 610 et seq.5. Baird. Brenchley's Cruise of H.M.S. " Curagoa."6. Beck. MSS.7. Canefri. Ann. Soc. Mai. Belgiqne, Vol. xv. p. 50.8. Chenu. Man. Conch.

628 EDGAR A. SMITH.9. Chemnitz. Conch. Cab., Vol. x.10. Clessin. Conch. Cab., Ed. 2.11. Crosse, (a) Jon7vi. de Conch., Vol. xiii. ;(b) Rev. et Mag. ZooL, Vol. x. 1858.12. Deshayes. (a) Maillard's L'lle de la Reunion, Vol. ii.; (6) Joiirn. de Conch., Vol. vi.(c) Proc. Zool. Soc, 18.54, pp. 317 et seq.;{d) Proc. Zool. Soc, 1859, pp. 270 et seq.13. Delessert. Recueil de Coquilles.14. D'Orbigny. Moll. Cuba, Vol. ii.16. DuNKER. Index Moll, maris Japan.16. Gmelin. Syst. Nat.17. Gould. Otia Conchologica.18. Gray, (a) Proc. Zool. Soc, 1834, pjx 57 et seq.; (b) (? Gray) Appendix, King'sAustralia, Vol. ii.19. Hanley. (a) Thes. Conch., Vol. i. ;{b) Ipsa Linn. Conch.20. HiND.s. {a) Voyage "Sulphur" Mollusca; (b) Thes. Conch., Vol. i.2 1 . LssEL. Malacol. mar Rosso.22. JoussEAUME. Rev. et Mag. de Zool, Vol. xxiii.23. KiENER. Coq. viv.24. KoBELT. Conch. Cab., Ed. 2.25. Krauss. Sudafr. Moll.26. Martens. Mobius' Meeresfauna Mauritius, Mollusken.27. Melvill. {a) Mem. Manchester Soc, Vol. xu. ;(b) Journ. Conch., Vol. x.28. Melvill and Standen. (a) Journ. Conch., Vol. viii. ; (6) Journ. Linn. Soc, Vol. xxvii.p. 150 et seq.29. Melvill and Sykes. Proc Malac. Soc, Vol. iii.30. Morgh. Cat. Conch. Yoldi.31. Pease, (a) Anm: Jour. Conch., Vol. in.; (6) Proc. Zool. Soc, 18(30, p. 397 et seq.32. Pfeiffer. Co?ic/i. Cab., Ed. 2.33. Philippi. (a) OwicA. C«6., Ed. 2; {b) Abbild., Vol. in.34. Pilsbry. Man. Conch., Vols. xi. xii. xiv. xv. xvn.35. QuoY et Gaimard. Voyage "Astrolabe."36. R^CLUZ. Journ. de Conch., 1850.37. Reeve. ConcJi. Icon., Vols. i. n. in. iv. v. vi. vui. ix. x. xi. xn. xiii. xiv. xv.XVII. XX.

MARINE MOLLUSCA. 62938. RoMER. Novitat. Conch., Monogr. Venus, Vol. i.39. Smith, (a) "Challenger" Lamellihranchiata ; (6) Proc. Malac. /Soc, Vol. i. ;(c) Proc.Malac. Soc, Vol. iii. ;(d) Proc. Malac. Soc, Vol. v.; (e) Journ. Linn. (S'oc, Vol. xii. ; (/) ProcZool. Soc, 1878, pp. 804 et seq.; (g) "Alert" Report.40. SowERBY. («) Co)ich. Icon., Vols. XV. xvii. xviii. xix. xx. ;(b) Thes. Conch.. Vols.I. II. III. IV. v.; (c) " Tankerville" Cat, Appendix; (d) Proc. Malac Soc, Vol. i. ;(e) Proc.Malac. Soc, Vol. iv.41. Tryon. 3Ian. Conch., Vols, ii. iv. VI. viii. ix.42. Vanatta. Proc. Acad. Nat. Sci. Philad., Vol. Liii.43. Weinkauff. Kuster's Conch. Cab., Ed. 2.EXPLANATION OF PLATES.PLATE XXXV.Fig. L Cryptojihihalmus minikoiensis, dorsal view.Fig. 2. „ „ shell.Figs. 3, 4. Marginella picturata, var.Fig. 5. Ultra (Cosiellaria) angustissima, n. sp.Fig. 6. Nassa maldivensis, n. sp.Fig. 7. „ „ operculum.Fig. 8. „ „ var.Fig. 9. „ mulukuensis, n. sp.Fig. 10. ,,,,operculum.Fig. 11. ,, siibtranslucida, n. sp.Fig. 12. ,, disjmrilis, n. sp.Fig. 13. Murex (Ocinehra) submissus, n. sp.Fig. 14. Sistrum iostcmia, A. Adams.Fig. 15. Triforis lilaceocinctus, n. sp.Fig.

630 EDGAR A. SMITH.Fig. 22. Natica euzona, operculum.Fig. 23. Scalaria (Cirsotrema) texta, n. sp.Fig. 24. Liotia squamicostata, n. sp.Figs. 25, 26. Thalotia maldivetisis, n. sp.Fig. 27. Perrinia atigidi/era, A. Adams.PLATE XXXVI.Fig; s. 1,2. Ethalia rhodomphala, n. sp.Fig.3.Ischnochiton hululensis, n. sp.Fig.Fig.Fig.Fig.Fig.Fig.Fig-Fig.Fig.Fig.Fig.Fig.Fig.Fig.Fig.Fig.Fig.Fig-4.5.6.7.8.9.\0.1112,1314.15161718192021„ „ anterior valve.„ „ median „„ „ posterior ,,„ maldivensis, n. sp.„ „ anterior valve.,, „ median „,, ,, posterior ,,„ Jeliduensis, n. sp.„ ,,anterior valve.„ „ median „„ „ posterior ,,Pecten cooperi, n. sp. left valve.,, sculpture magnified.„ right valve.„ sculpture magnified.maldivensis, n. sp. left valve.„ right valve.Janira garditieri, n. sp. left valve.Fig. 22„ ,,right valve.Fig.Fig.Fig.Fig.23242526Amussiuni pauciliratum, n. sp. exterior.,, ,,interior.Cardium levisulcatum, n. sp. right valve.„ „ dorsal view.

Fauna and Geography Mai 1. ;:-;- ,Aiid bai'CMUivc- Plate XXW."^^10.,Wr.mk12,13.16.17.14.19,211518.22.23.Edgar Smith - MoUusca.

Plate XXXVI.mii>>-*"^-îi,.•^16./?«5f15.^18.f/.#,..*^:/-i/V^^^.17.^19./^fel"^,.••;./;///iiii20.«-21.11.22.26.CliE ^//flson Cambridge,Edgar SiTLith - Mollusca.

THEENTEROPNEUSTA.By R. C. Punnett, M.A., Fellow of GonviUe and Caius College, and Demonstratorof Comparative Anatomy in the University of Cambridge.(With Plates XXXVII.—XLVI. and Text-figs. 120, 121.)CONTENTS.Introduction, p. 631. Systematic account, p. 631. Some anatomical points, (1) the pygochord,p. 659, (2) the lateral septa, p. 659, (3) the branchiae, p. 660. The formation of the gonads,p. 660. Variation in Ptychodera fiava, p. 662. Metamerism in the Enteropneusta, p. 669.INTRODUCTION.The collection of Enteropneusta brought together by Mr Stanley Gardiner is the mostextensive hitherto made in any single locality, not only in the variety of forms, but also inpoint of numbers. To Mr Gardiner's recognition of the importance of collecting considerablenumbers and to his perseverance and zeal I owe this opportunity of making someobservations on the variation shewn by the genus Ptychodera, a field hitherto unexplored.The material is on the whole excellently preserved, and I would here express my thanksto Mr Gardiner for entrusting to me so interesting a collection. I am also greatly indebtedto Mr Forster Cooper for the coloured sketches from life which form the first plate to thispaper. With the account of the Laccadive and Maldive forms I have incorporated a descriptionof an interesting new form kindly placed in my hands by Mr Crossland, who collectedit in Zanzibar. Many regenerating specimens occurred in Mr Gardiner's collection. TheseI hope to make the subject of a subsequent paper.Fam. 1. Harrimaniidae.Fam. 2. Glandicipitidae.Spengelia porosa, Willey, 1898 ..........SYSTEMATIC ACCOUNT.'(Not represented.)FAQE633Sp. maldivensis, n. sp.Collar relatively very short with cornua of nuchal skeleton extending toextreme hind end. Dorsal septum throughout collar. Medium proboscis septumvery short. Dermal pits very small. No median gonads in post-branchial region. 635'The classification adopted is that recently revised by Spengel.81—2

632 B. C. PUNNETT.Willeyia hisulcata, nov. gen., n. sp.PAOECollar and proboscis both very long. Branchial part of cesophagus smallcompared with ventral portion. No dermal pits, synapticula or median gonads . 637Fam. 3.Ptychoderidae.Balanoglossus carnosus, Willey, 1899 .........B. parvulus, n. sp.640Small form with very short branchial region. Genital pleurae small andwidely separate at collar. Gill pouches without ventral caecum. No accessorygonads. Collar cord with continuous lumen ........ 640Ptychodera Jlava, Eschscholtz, 1825.Var. parva, nov. var.Small form. Proboscis cavity large and with longitudinal muscles gatheredinto distinct separate bundles. Both proboscis pores functional. Number ofdorsal roots 2— 3. Branchial region short, i.e. less than 2 x collar length.Collar cord with continuous lumen. Nuchal cornua well developed . . . 644Var. laccadivensis, nov. var.Large form. Proboscis cavity large and with longitudinal muscles gatheredinto distinct separate bundles. Number of dorsal roots 3—6. Branchial regionon the average more than 2 x collar length. Collar cord wth continuous lumen.Nuchal cornua well developed .......... 646Var. maldivensis, nov. var.Moderately large form. Proboscis cavity fairly large with longitudinalmuscles gathered into distinct separate bundles. Dorsal roots only 1—2.Branchial region averages less than 2 x collar length. Collar cord with continuouslumen. Nuchal cornua short ......... 648Var. saxicola, nov. var.Medium sized form. Proboscis cavity fairly large with longitudinal musclesgathered into distinct separate bundles. Dorsal roots 2—4. Branchial regionvery short, averaging only slightly more than collar length. Lumen of collarcord with tendency to obliteration. Nuchal cornua short ..... 650Var. gracilis, nov. var.Small and rather slender form. Proboscis cavity fairly large with longitudinalmuscles gathered into distinct separate radial bundles. Dorsal roots2— 3. Branchial region short, averaging about half as long again as collar length.Collar cord with continuous lumen. Nuchal cornua rather short .... 651Var. muscida, nov. var.Small, rather stoutly built form. Proboscis cavity much reduced and longitudinalmuscles not gathered into distinct separate radial bundles. Branchialregion fairly long, averaging more than 2 x collar length. Lumen of collar cordwith marked tendency to oblitei'ation. Nuchal cornua rather short . . . 653

THE ENTEROPNEUSTA. 633Var. cooperi, nov. \ar.PAOEVery small form with short proboscis and collar. Proboscis cavity smulland longitudinal muscles not gathered into distinct separate radial bundles.Branchial region rather more than 2 x collar length. Lumen of collar cordwith tendency to obliteration. Nuchal cornua very long, overlapping branchialregion 655Pt. viridis, n. sp.Medium sized form, Proboscis markedly longer than collar. Prevailingcolour in life green. Proboscis cavity very small and longitudinal muscles notgathered into distinct se[)arate bundles. Branchial region very short. Lumenof collar cord completely obliterated ......... 656Pt. asyinmetricn, n. sp.Rather small form. Proboscis cavity small and longitudinal muscles notgathered into distinct separate radial bundles. Lumen of collar cord almostobliterated. Gonads asymmetrical, on left side only ...... 657fig. 11).Spengelia porosa, Willey, 1898 (PL XXXVIII. fig. 13; PL XLI. figs. 5, 7; PL XLII.Locality, etc. This species was found in three localities, viz.(a) Goifurfehendu AtolL Goidii, where it was obtained from the sandy shore closeto the east of the island in the sand below the weed and under some square slabs ofbeach sandstone in company with Pt. flava, var. muscula. (All this material was muchmacerated.)(6) S. Mahlos Atoll, Mamaduwari, where it was very common under the beach sandstonemasses to the north of the island.(c) Male Atoll, Hulule. A single specimen was obtained from a hole in a coralmass dredged from 7 fathoms in the lagoon of Hulule Atoll. (Anterior end only.)External features. In Willey's specimen the proboscis was of a rich yellow colour,the collar bright orange and the body generally of a dull yellow colour. No observationson the colour of the Maldive specimens have reached me except of the single one fromHulule. Mr Stanley Gardiner noted that the colour here was uniformly pale lemon. Muchstress however cannot be laid on the difference in colour from Willey's specimen as thisHulule individual was represented only by the pre-genital part of the animal and was arather small specimen.The general appearance of the Maldive forms agrees closely with the figure given byWilley ('99, PL XXVII. fig. 8). The size also is about the same though the length ofthe proboscis as compared with the collar is on the whole slightly greater than in Wîlley'sspecimen. The relative length of the branchial region to the collar is on the average about6, as in Willey's animal. In the single entire specimen in the collection the total lengthwas 215 mm. The branchial region is faiily constant in its length relative to the collar inindividuals of different sizes. The number of gill slits increases markedly with the size ofthe animal. These facts are brought out in the following table of measurements:

634 R. C. PUNNETT.No. of Specimen.(1) (2) (3) (4) (5) (6) (7) (8)Length of collar 3 3 3 2-5 2-5 25 1-5 ——„ „ proboscis 5'5 6 5 5 4'5 4'5 4„ „ branchial region ... 20 17 16 17 17-5 17 10-5 9Total length _ 215 — — — — — —Branchial length^.^ ^.^ ^.3 ^.^ ^ 6-8 7-Collar lengthNo. of gill slits 116 — 110 104 102 88 74 58The specimens are given in order of size, (1) being the largest, (8) the smallest.In his account Willey states that external liver saccules are not present in the alliedspecies S. alba ('99, p. 277), "although, when fresh, the annular ridges were found to beturgid and to present the appearance of rudimentary saccules, an appearance which wasalmost entirely lost after preservation." He was unable to state anything with regard tothis region in Sp. porosa as his only well-preserved specimen lacked the post-genital portionof the body. External liver saccules are nevertheless present in Sp. porosa, though they arenot very prominent (PI. XXXIX. fig. 13). That they project somewhat from the dorsalsurface may be more readily seen in transverse sections (see PI. XLI. fig. 5). They arealso characterized by their green colour.Pig. 120. Schematic reconstruction of anterior end of Sj). porosa, x 10. The dotted line in front of the stomoohordindicates the forward extension of the pericardial auricles. For lettering see p. 676.Internal structure. To the full and careful account given by Willey I have littleto add, and that chiefly in regard to the jjost-genital region which, as has already beenmentioned, was absent in his specimen.Proboscis. In Willey's specimen the ventral recurrent vessel was independent of theventral septum. In the three siêcimens which I have examined it runs up to the centralcomplex in the anterior free edge of the ventral septum (Text-fig. 120, vrv.).Willey states that the median muscular system extends over about ^ of the lengthof the proboscis. It is not quite so long in the Maldive forms and may be exceedinglyshort (Text-fig. 120, mdv.), not extending quite so far forwards as the pericardial auricles.

egionTHE ENTEROPNEUSTA. 635The vermiform process is usually well-marked and coextensive with the dorso-ventralmuscles. In the instance where these muscles were reduced the vermiform process hadaltogether disappeared.Collar. Willey states that " there is no dorsal septum in the collar, except the foldof basement-membrane associated with the first vestigial root, which is probably to beregarded as a vestige of the dorsal septum. On the other hand the ventral septum hasan unusual forward extension, commencing a short distance behind the region of bifurcationof the nuchal skeleton." In the Maldive forms the dorsal septum is present though onlyat the hind end of the collar (Text-fig. 120, ds.), whilst no ventral septum is to be found.A vestigial root was found in one of the three specimens examined. It was, however,very small and did not reach to the epidermis (Text-fig. 120, ?•.). Both anterior and posteriorneuropores are very deep, so that only about ^ of the collar cord is devoid of a continuouslumen. This portion contained traces of a cavity.In his specimen Willey found that the cornua of the nuchal skeleton extended to theextreme posterior end of the collar. This may be the condition in the Maldive specimens,whilst on the other hand the hindermost quarter of the collar may be without cornua.The collar canals open into the first branchial pouch and I have been unable to findthe truncal canals described by Willey.Trunk. The branchial and genital regions agree closely \vith Willey's account.In the hepatic region there is no internal circular musculature. The longitudinal musclesare gathered into three bands on either side, viz. a dorsal, a ventral, and a lateral one(PI. XLI. fig. 5). Consequently there are in this region two longitudinal areas where nomuscle fibres intervene between the intestinal wall and the epidermis.In the intestinal .there is a longitudinal dorsal groove on either side whichshews slight depressions at intervals (PI. XLI. fig. 7). The circular muscles form a completering round the body here but the longitudinal muscles are wanting beneath the grooves.The intestine itself is small and laterally compressed, the body cavity being occupied bystrandsof connective tissue.Although there are several small points of difference between the Maldivan forms andWilley's specimen I have thought it best, in view of the considerable variations shewn onthese very points, not to separate these forms from Willey's. It is possible that when morematerial is forthcoming the differences may be found to be sufficient to separate them asdistinctvarieties.Spengelia maldivensis, n. sp. (PI. XLI. figs. 6, 8; PL XLII. fig. 20).Locality, etc. Hulule. From beach sand-rock. A single specimen only was obtainedand this lacked the posterior part of the body, which was broken away in the genital region.External features. A small form and the colour after preservation is quite white.The total length of the fragment obtained was 21 mm. Of this the proboscis measured4 mm., the collar 1'8 mm. (with a width of 3 mm.), whilst the length of the branchial regionwas 6 mm. Characteristic is the shortness of the collar, the length of which is not muchmore than half its width. The width of the genital region did not exceed 3 mm.

636 R. C. PUNNETT.Internal structube.Proboscis. The outer circular muscle layer is very delicate. The proboscis contains acentral cavity which is not divided into right and left portions in fi-ont of the centralcomplex. The long vermiform process of the stomochord runs forwards dorsal to the cavity(PL XLI. fig. 8, v.). It is somewhat fragmented in places. Where it joins the stomochordj)roper appears the ventral septum separating the ventral coelom into two portions, whichdo not subsequently join with one another. A dorsal septum also occurs in front of thejunction of the pericardium with the basement membrane below the epidermis. The lumenof the stomochord is well marked in some places though obliterated in others. The lumenof the lateral diverticula is only patent at the extremity of each. The chondroid tissue iswell developed. The nuchal skeleton possesses a well-marked keel.The left proboscis pore alone is present. The right perihaemal cavity reaches forwardsconsiderably further than that of the left side (PI. XLI. fig. 6, ph.).The pericardial auricles are very short.Collar. The outer longitudinal muscles are jjoorly developed and there is no circularlayer. The collar is without a cavity. The dorsal septum extends through the length ofthe collar, whilst the ventral one is only found complete at the posterior end.The nerve cord is practically solid throughout, only very faint traces of a lumen beingdiscoverable here and there. There is no sign of any dorsal root.The cornua of the nuchal skeleton are long and reach backwards to the extreme hindend of the collar (PI. XLI. fig. 8, en.) and to some extent overlap the branchial region.The collar pores open into the first gill pouch, which possesses a small diverticulumreaching forwards for a short distance ventral to the collar canal (PI. XL. fig. 8, p. 1). Thisis doubtless the structure referred to by Willey ('99, p. 280) as the truncal canal. Inthe present species it possesses no trace of an opening into the perihaemal space, and thediverticulum differs in nowise histologically from the rest of the gill pouch, thus lendingno support to the morphological importance with which Willey is inclined to regard them.Trunk. The circular musculature is, as usual in this genus, found inside the longitudinallayer. In the branchial region the ventral portion of the oesophagus is almost as large asthe branchial division, the proportions being similar to those in Sp. porosa as figured byWilley ('99, PL XXXI. fig. 45). About nine synapticula are present on each gill bar. Adistinct but small post-branchial groove is present (PL XLII. fig. 20). The grooves intowhich the gill pouches open are produced backwards past the branchial region. They donot however exhibit the peculiar depressions found in Sp. porosa and Sp. alba which Willeyhas termed dermal pits. Too much stress must not be laid on their absence, however, asthe gonads are somewhat immature and it is possible that with their increase in size smalldermal pits might arise. There is little doubt that they would never reach the samedevelopment as in the above-named forms, a circumstance jirobably correlated with the smallersize of the species under consideration.In the branchial region both median and lateral gonads are present. In the genitalregion however the lateral gonads alone are present. The median gonads are always verysmall and are not nearly so numerous as the lateral ones.Though the above species has been created on the strength of a single imperfectspecimen yet in its short collar, its undivided proboscis cavity, the reduction or absence of

THE ENTEROPNEUSTA. 637its dermal pits and median gonads, it exhibits structural differences sufficient to separateit at once from Sp. porosa and Sp. alba, the only two species of this genus hitherto described.Willeyia bisulcata, nov. gen., n. sp. (PL XXXVIII. figs. 14, 23; PI. XXXIX. fig. 29;PI. XLI. figs. 9, 10; PL XLII. figs. 12—16).Locality, etc. This species was fairly abundant at Zanzibar, whence portions of twospecimens were brought back by Mr Crossland. They were obtained by digging in mudon which Zostera was growing atlow-water mark.External features. To judge from the fragments the length of this species must inthe entire state be considerable. The proboscis is about double the length of the collarand is marked both dorsally and ventrally by a deep median gi-oove (PI. XXXVIII. fig. 14).Its width is somewhat greater than its dorso-ventral depth. The collar is long and issomewhat broader behind than in front. Near its posterior end there is a well-markedcircular groove. In one of the two specimens available, which was somewhat larger thanthe other, the length of the proboscis was 14 mm., that of the collar 7 mm. The averagebreadth of both was about 4 mm. The branchial region and trunk have each a breadthsomewhat less. In the specimen above alluded to some 32 mm. of the branchial regionwere still attached to the collar. No external liver saccules were visible on any of thefi-agments. Probably they are not present. No portion of the caudal region was preserved.With the exception of the proboscis, which is somewhat dorso-ventrally flattened, the wholebody of the worm is more or less cylindrical. When living the animal was of a uniformcream colour.Proboscis. The epithelium is high though almost destitute of glands. It shews a verydistinct layer of elongated nuclei about its middle and numerous small rounded nuclei in itsdeeper portion. The layer of nerve fibrils is very distinct and well developed throughoutthis region and rests on a fine but clearly marked basement-membrane. The circular musclelayer is strong, being nearly half as thick again as the nervous layer. The longitudinalmuscles are well-developed, filling the greater portion of the proboscis (PL XLII. fig. 12).The nervous layer is thickened in the grooves.The proboscis coelom consists of a right and a left cavity which are entirely separatethroughout. They are lined by a well-marked epithelium which is considerably thickenednear the middle line (PL XLII. fig. 12 and PL XXXIX. fig. 29). The two divisions of thecoelom are surrounded by a common layer of circular muscles (PL XLII. fig. 12). The leftdivision of the proboscis coelom communicates with the exterior by a large pore (PL XLI.fig. 9). The right division ends blindly. No dorsal septum is present but there is a wellmarkedventral septum, at the upper edge of which runs the ventral recurrent vessel ofthe proboscis (PL XLII. figs. 11 and 12, and PL XXXIX. fig. 29, vrv.). This septumsprings from almost the tip of the proboscis and does not become complete until shortlybehind where the pericardium arises. Here the ventral vessel becomes connected with thevessels of the glomerulus. On either side of the middle line are found dorso-ventralmuscles, the dorsal ones being more marked than the ventral. Both converge towards thevermiform process of the stomochord where this structure is found (PL XXXIX. fig. 29).The stomochord exhibits a well-marked lumen throughout, both in its central portionand in the lateral diverticula. Anteriorly it is produced forwards as a vermiform processwhich is about | of the length of the rest of the stomochord (PL XLII. fig. 10).G. II. 82

638 R. C. PUNNETT.The nuchal skeleton is strongly developed, occupying a large portion of a transversesection in the region of the proboscis stalk (PL XLI. fig. 9). The keel is strongly developedbut much blunted, its side to side diameter being greater than the dorso-ventral one.The pericardium is provided with two small " auricles" reaching forward about -^ mm.from the main structure on either side.Collar. The epithelium of this region is high and fairly well provided with gland-cells.The posterior part of the collar on either side of the circular furrow is characterized by amore highly glandular zone. In the preserved specimens this region is somewhat paler incolour than the rest of the collar. The nerve fibre layer is distinct, whilst, as in theproboscis, the basement-membrane is thin. There is no layer of cu-cular muscles outside thelongitudinalmusculature.The collar coelom is entii-ely filled by longitudinal muscle fibres and connective tissue,Avith the exception of a small space round the opening of each of the collar funnels. Thedorsal septum is complete throughout the entire length of the collar. The ventral septumis lacking only at the extreme anterior end (PI. XLI. fig. 10).The median nuchal skeleton is long whilst its cornua are exceedingly short (PI. XLI. fig. 10),a feature in which this genus differs markedly from the remaining members of the family.The cornua embrace nearly f of the total cii'cumference of the oesophagus.The collar cord exhibits a well-marked anterior and a smaller posterior neuropore. Theanterior neuropore especially reaches some way dov*Ti into the collar (PL XLI. fig. 10).Towards its hinder limit it becomes somewhat separated off fi-om the nerve cord on thedorsal surface of the lattei-. It is lined with a definite epithelium somewhat glandular andrichly provided with cilia. The nerve cord itself is quite solid and is almost entirely surroundedby a layer of nerve fibres (PL XXXVIII. fig, 23). In its hinder portion it shews awell-marked ridge projecting up towards the dorsal septum. This ridge is filled with cellscontaining a yellowish-brown pigment. These cells reach a little way into the nerve cordand similar cells are also to be found in the perihaemal spaces (PL XXXVIII. fig. 23).Pigment has previously been described by Spengel ('93, p. 134 and Taf 7, figs. 2, 12, 14)in the collar cord of Balanoglossiis apertas. Without going so far as Willey ('99, p. 316)in claiming that the dorsal roots are homologues of the vertebrate pineal eyes it is yetconceivable that these aggregations of pigment may serve for the perception of light rays.Besides this small dorsal ridge there occurs no representative of dorsal roots in W. bisulcata.From the anterior part of the collar cord passes off on either side a well-marked nerveto the layer of nerve fibrils beneath the oesophageal epithelium. These I have termed theoesophageal nerves (PL XLII. fig. 16, on.).With regard to the histology of the collar cord it may be stated that giant cells, suchas Spengel ('93, p. 609) has described for several species of Enteropneusts, are absent.Certain of the ganglion cells near the dorsal surface attain a somewhat larger size, butthis does not exceed 20—25 fi. Faint vestiges of the remains of cavities in the cord arevisible here and there under a high power. The pigment referred to above is found alongthe whole length of the cord.The perihaemal spaces are well developed and ventrally contain transverse muscle fibres.They do not come into contact with one another until just in front of the point wherethe cornua of the nuchal skeleton diverge. Anterior to this they are widely separated bythe stomochord.

THE ENTEKOPNEUSTA. 639The right and left peripharyngeal spaces are separate except at the hind end of thecollar, where they meet ventrally. As they reach forwards their ventral borders slope obliquelyand gradually upwards until the two borders merge at a spot dorsal to the oesophagus,where the circular muscles which the spaces contain are inserted into the nuchal skeleton.Where the periphar^-ngeal spaces are deficient ventrally the oesophagus is still provided witha layer of circular muscles probably derived from the longitudinal musculature.Branchial region. One of the chief characteristics of the present species as comparedwith the other members of its family lies in the fact that the branchial portion of theoesophagus is of considerably less e.xtent than the remainder (PI. XLII. fig. 13). This resultsin the septal and tongue bars being relatively short. The musculature is in this regionwell-developed. Beneath the powerful longitudinal layer is a sheath of circular fibres extendingup to the lower ends of the gill pouches. Noteworthy is the position of the ventralnerve cord which projects so far inwards that it almost abuts against the circular muscles.Of the posterior branchial region it is not possible to give any account, since I have beenunable to identify it among the fragments which have come to me. Synapticula are absent.The first three gill pouches are dorsally confluent, forming a chamber with a single externalpore into which opens the collar pore. No trace of truncal pores is to be found resemblingthose described by Willey ('99, pp. 273, 280) for Spengelia. The branchial region isprobably devoid of gonads, or if these occur here it is only in its most posterior portionthat they are to be found. In the specimen with the gi-eater attached length of branchialregion, this was about 4|- times the length of the collar. No gonads were present evenat the extreme end of this fragment.SchizocardiumGlandicepsSpengeliaWilley iaPericardial auricles verylarge.Pericardial auricles verysmall.Pericardial auricles small.Pericardial auricles small.No dermal genital pits.No dermal genital pits.Dermal genital pits.No dermal genital pits.(Esophageal part of branchialsac very small.CEsophageal part of branchialsac reduced to abroad tract.CEsophageal part of branchialsac a deep groove.CEsophageal part of branchialsac much largerthan branchial part.Peripharyngeal cavities.No peripharyngeal cavities.Peripharyngeal cavities.Peripharyngeal cavities.Comua of nuchal skeletonto posterior collar region.Comua of nuchal skeletonto posterior collar region.Comua of nuchal skeletonto posterior coUar region.Comua of nuchal skeletonnot found in posteriorhalf of collar.No median gonads.Median gonads present orabsent.Median gonads present orabsent.No median gonads.Synapticula.No synapticula.Synapticula.No synapticula.External liver saccules.No external liver saccules.External liver sacculespresent or absent.(?)Ventral proboscis septumlong and reaching vermiformprocess.Ventral proboscis septumshort and not to vermiformprocess.Ventral proboscis septumshort and not to vermiformprocess.Ventral proboscis septumvery long but not tovermiform process.Genital region. The longitudinal muscles are still strongly developed (PI. XLII. fig. 14)but the circular layer has now disappeared. The ventral nerve cord still shews the peculiar82—2

640 R. C. PUNNETT.deeply sunk position which it exhibited in the branchial region. Subgenital pits such asWilley found in Spengelia ('99, p. 274) are absent. The gonads form a single row oneither side of the body. Ripe spermatozoa occurred in the specimen from which the sketchof the genital region was taken.As belonging to the family Glandicipitidae there have already been described threegenera, viz. Schizocardiuni, Glandiceps, and Spengelia. It cannot be said with any confidencethat Willeyia bears a closer resemblance to any one of these genera than to another.Features which separate it from all these three are the shortness of the nuchal cornua,the comparatively small extent of the branchial portion of the oesophagus as compared withthe digestive, and possibly also the absence of gonads in the branchial region. With respectto other features of generic importance Willeyia resembles now one genus and now another.To which of the above genera it bears most resemblance with respect to the more salientfeatures of its anatomy may be gathered from the appended table, p. 639.Balanoglossus carnosus, Willey, 1899 (PI. XXXVII. fig. 3).Locality, etc. The greater portion of a very large specimen was obtained at Minikoi,at the base of a cyluidrical casting in the sand flat lagoon. Fragments of the same specieswere also found at Hulule in sand under a large Porites mass close to the boulder zone.A coloured sketch was made of the Minikoi specimen by Mr Forster Cooper beforepreservation. This is reproduced on PI. XXXVII. fig. 3, and shews the natural colours ofthe animal. A bright yellow line occurred mid-ventrally which was probably the nerve cord.The dimensions of this large specimen were taken by Mr Gardiner while it was yetalive. I have also taken them on the preserved specimen and the results of both are asfollows : Living PreservedLength of proboscis beyond collar... 9 mm. 3 mm.Breadth „ 5 „ —Length of collar 22 „ 13 „„ „ branchial region — 60 „„ „ genital pleurae — 204 „„ „ animal obtained 440 „ 35.^ „When alive and undamaged the animal probably exceeded 60 cm. in length, and possessedan average diameter of 10—12 mm. The above measurements agree fairly well with thosegiven by Willey ('99, p. 248). There appears to be considerable vai-iation in the relativelength of the branchial region which may be somewhat less than double the collar length,or may be as much as four times as much. The present specimen agrees with the largestof Willey 's specimens, which it rivals in size, in having a relatively long branchial region.In addition to the above fairly complete specimen a number of jelly tubes were foundat the surface in castings similar to that which marked the position of the large worm.These tubes were much distended with sand, and of a transparent straw colour with bi-ightyellow mid-dorsal and mid-ventral lines. The edge of the free (= anal ?) end was markedby brown-black jaigment. Doubtless these tubes are the broken off caudal ends of thisspecies. Like Pt. flava (see p. 646) it may have developed the habit of autotomy.Balanoglossus parvulus, n. sp. (PI. XXXVIIL figs. 15, 18, 22; PI. XXXIX. fig. 24;PI. XLI. figs. 1—4).Locality, etc.Represented only by a fragment comprising the anterior end and includingthe proboscis, collar, branchial region, and a portion of the genital region. From Mahlos Atoll.

THE ENTEROPNEUSTA. 641External features. An exceedingly small form. The proboscis is nearly r5mm. inlength and is somewhat longer than the collar (PI. XXXVIII. fig. 18). The branchial regionis about half as long again as the collar. Width of collar and proboscis about 1'5 mm.The width of the branchial region is not quite so great, whilst the genital region is lessthan 1 mm. wide. The anterior border of the collar is rather \vider than the rest of thispart of the animal and is somewhat crinkled. Posteriorly the collar shews a well-markedcircular furrow (PL XXXVIII. fig. 18, t.f.). The genital pleurae are small and are widelyseparated from each other where they join the collar. The mature and swollen gonads in thisspecimen cause the edges of the pleurae to assume a somewhat beaded appearance.Proboscis. The proboscidial coelom is almost entirely filled by connective tissue andmuscle fibres. A delicate layer of longitudinal muscle fibres is found beneath the basementmembrane, but circular fibres are absent. Traces of a dorsal septum are to be found slightlyin front of the pericardial sac. The ventral septum is complete at a level shortly beforethat at which the glomerulus ends ; it carries the ventral glomerulus vessels. The ventralproboscis coelom is packed with, muscle fibres and connective tissue except at its extremeposterior end where the ventral septum is lacking (PI. XXXVIII. fig. 22, v.c). A racemoseorgan is not present.A single median proboscis pore is present, placing the left division of the dorsal probosciscoelom in communication with the exterior (PI. XXXVIII. fig. 22, p.p.). The right moiety ofthe dorsal proboscis coelom ends blindly. Throughout its whole extent the stomochord shewsa well-marked lumen. The lateral diverticula of the stomochord are small (PI. XXXVIII.fig. 22, S.C.). The nuchal skeleton is provided with a deep narrow keel (PI. XLI. fig. 3, sk. 1).The chondroid tissue in this region is exceedingly scanty.Collar. The collar epithelium is very thick (PI. XXXIX. fig. 24, ep.). The glandular zonecommences at the level where the cornua of the nuchal skeleton terminate and reaches tothe commencement of the collar funnels. The outer longitudinal muscle layer is well-marked,particularly in the anterior and middle regions of the collar (PI. XXXIX. fig. 24, el.). Theinner longitudinal layer is also strongly developed. No circular muscle fibres are present.The collar coelom is entirely filled with muscle fibres and connective tissue except fora very small space on either side of the dorsal septum. This last-named structure is firstfound immediately behind the first dorsal root in the middle of the collar region. Tracesof a ventral septum exist but in no place is it complete. The collar funnels are of theusual form and open into the first gill pouch.The cornua of the nuchal skeleton extend half-way round the oesophagus. In lengththey are short, being only about i of the total collar length.The collar cord is tubular containing a single axial canal (PI. XXXVIII. fig. 15) surroundingwhich are the ganglion cells. The layer of dorsal ganglion cells (PI. XXXVIII.fig. 15, gcd.) is thin, being best marked in the region where the first and second dor.salroots are given off. Above it is a much attenuated layer of nerve fibrils. The ventralganglion cells {gcv.) are much more numerous and in transverse section are seen as a V-shapedmass shewing a bifurcation at the point of the V. The layer of nerve fibrils surroundingthem is well-developed. Separating the dorsal and ventral ganglion cells on either side isa layer of large oval vacuolated cells—probably gland cells from which the secretion hasbeen ejected or dissolved out. Some deeply staining mucoid substance is to be found inthe medullary canal. Here and there occur ganglion cells rather larger than the rest,

642 E. C. PUNNETT,but no giant cells are present such as have been figured by Spengel for B. apertus('93, Taf. 7, fig. 18). Except at its anterior end the collar cord is sunk in the perihaemalspaces which embrace it on either side and which may posteriorly reach nearer to the dorsalsurface than the cord itself. The medullary canal communicates with the exterior by theanterior and posterior neuropores.The first two dorsal roots are large, close together, and contain nerve fibrils but aredevoid of a lumen. They sf)ring from a common crest and reach the epidermis where theirnerve fibrils fuse with the nervous layer of the skin. Behind these are two or three smallincomplete roots with traces of a lumen but without nerve fibrils.A well-marked jêripharyngeal space surrounds the oesophagus (PI. XXXIX. fig. 24, pph.)reaching dorsally to where the comua of the nuchal skeleton diverge, and ventrally somewhatanterior to this point.Branchial region. This region is characterized by the small genital pleurae whichare widely separate at their junction with the collar. At the base of the pleurae openthe gill pouches (PI. XLI. fig. l,bp.) which are not provided with ventral caeca. The branchialand digestive portions of the oesophagus are approximately of equal size. Gonads are notfound in the anterior fourth of the branchial region. Not more than six synapticula arepresent on either side of the tongue bars. The post branchial canal is large and the posteriorincipient gill slits open into its ventral portion (PI. XLI. fig. 2, •>;).Genital region. The great bulk of this region is occupied by the gonads in themuch swollen pleurae (PI. XLI. fig. 4). Accessory gonads are not present, but each gonad isroughly two-branched, one division lying on either side of the lateral septum. The genitalpores are found on the edges of the pleurae at the spot where the lateral septum joinsthe epidermis. The single specimen was an adult female.Affinities. The genital pleurae of B. parvulus are relatively smaller than in any othermember of the genus and in this respect it apfiroximates to the genus Glossobalanus. Ofthe members of its own genus it bears most resemblance to B. apertus (Spengel, '93).In both the genital pleurae are widely separate where they join the collar, and this characterserves to distinguish these two species from all the other members of the genus exceptB. misakiensis (Kuwano, '02). Both B. parvulus and B. apertus are small forms withoutaccessory gonads, with a tubular collar cord, and with gill pouches unprovided with a ventralcaecum. The present species however differs from B. apertyts in the following features.B. parvuhisBranchial region but little longer than the collar.B. apertusBranchial region several times as long as collar.Gonads open at edges of genital pleurae.Gonad.s open on inner surface of genitalpleurae.No circular muscles tobody-wall.Feeble circularmusculature.Tongue bars with not more than 6 synapticula.Tongue bars with about10 synapticula.Medullary tube open at eitherend.Medullary tube closed at either end.Giant ganglion cells not found in collar cord.Giant ganglion cells present in collar cord.In B. parvulus also the keel of the nuchal skeleton is more marked, whilst the ventralproboscis coelom has undergone greater reduction. An idea of the relations of these twospecies with the other members of the genus may be gathered from the appended table.

THE ENTEROPNEUSTA, 643

644 R. C. PUNNETT.Ptychodera flava, var. parva (PL XXXVIII. figs. 16, 20, 21; PI. XXXIX. fig. 26;PI. XLIII. figs. 21—28 ; PI. XLIV. figs. 30—32 ; PI. XLVI. fig. 48).Locality, etc. From Turadu, S. Mahlos Atoll. About a dozen specimens procured, allmore or less of the same size. Thej were dredged fi-om 20 fathoms on a bottom ofcoarsesand.External feature.s. A small, somewhat short and slender form. The proboscis is ofabout the same length as the collar, which measures 2'5—3 mm. long, and is of approximatelythe same width. Behind the branchial region the body is not more than about 2 mm. wide.The liver saccules are not large and are slightly lobulated in the larger specimens. Thereis no apparent differentiation in colour among them as is usual in this species. The averagelength of the branchial region is about 1^ times the length of the collar, it being thuscomparatively short (vide p. 673). In the single entire specimen the total length wasonly 30 mm.Internal structure.Proboscis. A delicate layer of circular fibrils surrounds the longitudinal muscles whichare gathered together into radial bundles. A few longitudinal fibres are more closely gatheredround the central lumen of the proboscis and give it a definite outline (PL XLIII. figs. 21, 22).Dorso-ventral muscles are always found dorsal to the central complex anterior to the pericardium.The ventral proboscis septum is well-marked and reaches forwards almost or quiteto the tip of the stomochord. Both dorsal divisions of the dorsal proboscis coelom are incommunication with the exterior by the paired and equal proboscis pores (PL XLIII. fig. 26).In one case the proboscis pores opened together almost in the mid-dorsal line (PL XLIII.fig. 23), a condition of great rarity in this genus and recalling those obtaining in Balanoglossusapertus (Spengel, '94) and B. jamaicensis (Willey, '99, p. 293).The racemose organ is usually well-marked but is never lobulated. The lumen of thestomochord anterior to the lateral diverticula may be fairly distinct or almost obliterated.The lumen of each lateral diverticulum is large and open at the end but the portion bywhich it would communicate with the central lumen is usually almost or quite obliterated.Collar. Beneath the basement-membrane is found a fine but definite layer of longitudinalmuscle fibres. In the anterior jDart of the collar they are rather better developedand here directly enclose a delicate layer of circular muscles. No outer circular layer isfound over the gi-eater part of the collar. The anterior free cavity of the collar coelomis very spacious (PL XLIII. fig. 27, c.) extending as usual completely round the oesophagusin this region. Inside it are found the inner longitudinal muscles of the collar and withinthese again the peripharyngeal spaces with their enclosed circular muscle fibres. The dorsalcollar septum is as usual complete immediately behind the first root. In one case it wascomplete just anterior to this structure. The ventral septum may be absent or present inthe extreme hind portion of the collar.The nerve cord exhibits a complete lumen throughout, though sometimes with a fainttendency to obliteration. When this occurs the height of the cord as seen in transversesection is rather greater than usual and the gland cells are more numerous (cf PL XXXVIII.figs. 20 and 21). The number of the dorsal roots is either two or three. The majorityreach to the ectoderm.The cornua of the nuchal skeleton extend over nearly a quarter of the length of thecollar. Their length is apparently very fairly constant for this variety (cf. Table 1, p. 645).

THE ENTEROPNEUSTA. 645Table 1.Ptycliodera Jiava,var. parva.No. of specimen

646 R. C. PUNNETT.(PI. XLVI. fig. 48), springing from low clown. The branchial division of the oesophagus issomewhat more capacious than the ventral division of the oesophagus. The number ofsynapticula on the longest gill bars is either 7 or 8.Ptychodera flava, var. laccadivensis (PI. XXXIX. fig. 2.5; PI. XL. figs. 36, 38—40;PL XLV. fig. 43; PL XLVI. figs. 49, 51, 57).Locality, etc. Minikoi ; from lagoon close to edge of lagoon flat. It occurred in 4feet of water at low spring tides and was very abundant. The following notes were madeby Mr Gardiner."A few points about them are of interest, viz. (a) The tail part of the body, i.e.posterior ^, is merely a bag of sand and is often broken off if the animal be held stillby the head end. Under these circumstances the sand appears to be driven back by peristalticmovements of the whole body-wall more rapidly than it can escape, and as a resultthe posterior end simply breaks off. This I have verified by repeated observations underwater and I believe that it occiirs in life. (b) In distribution they are limited to theweed and to an area close to the edge of the flat, (c) Their natural position when aliveis within 4 inches of the surface of the sand. The head is close to the surface whilstthe body and tail are horizontal, (d) When thrown on to a sandy bottom the motion isvery feeble or nil if the body be full of sand. The posterior part is at once dehisced. Awriggling motion of the branchial and genital regions ensues, accompanied by powerful contractionsof the collar and extensions of the j)i'oboscis. The jjroboscis and collar' are veryslowly forced into the sand and then the body follows with comparative rapidity."External features. This variety shews a great resemblance to Pt. flava, var. caledoniensis(Willey, '99, p. 228) in general appearance. The largest complete specimens whichreached me are about 150 mm. in length, but fragments of larger specimens point to itsattaining a somewhat greater size. The proboscis is of about the same length as the collaror slightly longer. The anterior liver saccules are dark, the posterior lighter in colour. Thelarger liver saccules are lobulated along one edge, such lobulation being most marked inthe larger specimens. The length of the branchial and post-branchial genital regions aredealt with later (p. 663) in connection with variation in the grouf). The colour of theanimal in life was bright yellow or pale lemon, thus differing somewhat from Pt. caledoniensis,which is of a duller hue inclining to brownish.Internal .structure.Proboscis. Just beneath the basement-membrane occur a few delicate circular fibressurrounding the longitudinal muscles which are gathered up into radial bundles. Thesebundles project into the proboscis coelom, which has no well-defined boundary (PL XXXIX.fig. 25). Dorso-ventral muscles are usually to be found in the i-egion of the central complex.The ventral proboscis septum extends forwards as far as the tip of the stomochord. Thedecussation of muscle fibres on the dorsal side of the anterior portion of the proboscis iswell-marked as a rule, and a few circular fibres may be continued from it round the inneredge of the longitudinal muscles on the ventral surface of the proboscis cavity. The probosciscoelom of both sides may be placed in communication with the exterior by the two proboscispores. It as often happens however that the communication between the proboscis coelom'In Dolichoglossus pusilliis, whose movements form the subject of a paper by Kitter ('02), the proboscis appearsto play a relatively more important part.

THE ENTEROPXEUSTA. 64;and tile end vesicle opening by the proboscis pore is lacking. Sometimes this occurs onone side and sometimes on the other.Table 2.Ft, flava, var. laccadivensis.No. of specimen

648 R. C. PUNXETT.The racemose organ is always well-marked and in the larger specimens is usually somewhatlobulated.Collar. The cavity in the anterior part of the collar is usually spacious though notquite to the same extent as in Pt. parva. The dorsal septum is usually complete afterthe first root. The ventral septum may be entirely absent or, equally as often, it may befound in the hinder part of the collar. The number of proboscis roots varies from threeup to as many as six. The collar nerve cord usually has a distinct and continuous lumenwhich may rarely shew a tendency to become obliterated. The length of the comua ofthe nuchal skeleton is subject to a good deal of variation. It averages a trifle less thana quarter of the collar length.Trunk. In the branchial region the number of synapticula varies with the size of theanimal. The branchial region averages rather more than double the length of the collar(p. 665, Table 8). The post-branchial groove is well-developed, its length being about one-fifthof that of the branchial region. At its anterior level the genital folds are still of considerablesize (PI. XLVI. fig. 49). At the end of the post-branchial groove the folds havebecome much reduced (PL XLVI. fig. .51). The branchial portion of the oesophagus issomewhat smaller in section than the cesophageal portion (PL XLVI. fig. 57). A pj-gochordis present in the caudal region.Ptychodera flava, var. maldivensis (PL XXXIX. fig. 27).Locality, etc. From Maradu, Addu Atoll, where it was taken from sandy holes of thereef-flat. Fairly abundant. Two specimens also obtained from Hulule, on the east reefunderneath the stones of the boulder zone in sand.External features. In general shape and appearance this variety is indistinguishablefi'om laccadivensis to which it is very closely allied. Moreover the coloration in life wassimilar, this variety, like laccadivensis, shewing differentiation of the hepatic caeca into ananterior dark gi-oup and a posterior larger and lighter group.Internal structure. Exceedingly similar to that of laccadivensis from which varietyhowever the present one would seem to diifer on the following points. The proboscis cavityhas a definite outline as in parva (cf. PL XLIII. fig. 21) and does not reach up amongthe radial muscle bundles as in laccadivensis (cf. PL XXXIX. fig. 25).The racemose organ is on the whole somewhat smaller.The dorsal roots are less numerous, a feature in which this variety resembles cooperi.The cornua of the nuchal skeleton are relatively shorter than in laccadivensis.The branchial portion of the cesophagus is as large or larger than the ventral portion,whilst in laccadivensis it is always smaller.The branchial region is relatively shorter than in laccadivensis, averaging only r63 timesthe collar length as against 2'26 times in the latter variety, a difference which is the morestriking when one takes into account the comparatively large number of specimens examined(see below, p. 665, Table 8).The post-branchial groove of maldivensis isalso somewhat shorter than that of laccadivensis.In point of size the present variety is considerably smaller than laccadivensis, preservedspecimens of which may be as much as 150 mm. in length, whilst the largest specimen of

the enteropneusta.649Table 3.Pt. fiava, var. scudcola.vai'.maldivensis.No. of specimen(1)(2)(3)(4)(1)(2)Proboscis coelomSpaciousNot largeFaii'ly largeas (3)Fairly welldevelojiedand withdefiniteoutlineas(l)Collar coelomSpaciousSomewhatoccluded byconnectivetissueSpaciousSpaciousVeryspaciousas (1)Ventral proboscis septumNearly totip ofstomochordas (1)as(l)as (1)Nearly totip ofstomochordNot nearlyto tip ofstomochordDorso-ventral proboscis musclesPresentTracesas (2)AbsentPresentas (1)Dorsal collar septumCommencesjust anteriorto 1st rootCommences'5 mm. behind1st rootCompleteafter 1st rootas (3)Completeafter 2ndrootCompleteafter 1st rootVentral collar septumComplete inhinder partof collaras(l)Present inhinder partof collar butnot completeas (1)Absentas(l)Racemose organWell markedbut small andunlobulatedWell markedandlobulatedWell markedand slightlylobulatedDistinct butnot lobulatedSmall andunlobulatedas(l)Dorsal proboscis muscle decussationDistinctStrong. Alsoa few ventralcircularfibresWell marked.A few ventralcircularfibresStrong butno ventralcircularfibresNoFeeble.ventral circularfibresas(l)Dorsal roots*RRri-RrRRRRRRrRProboscis pores*LrLRIRLRLrIRNerve cord ....Length of post-branchial grooveLength of branchial regionLumen withtendency toobliterationin middlepart•43Lumen withmarked tendencytoobliterationLumencontinuous•22Lumen withslight tendencytoobliteration•25Lumencontinuous.Slight tendencytoobliterationposteriorly•16Lumencontinuous•IfiLength of comua x 100Length of collar17-110-119-415^08^4Circumference of branchial oes.Circumference of tesoph.ces.•33"5•38roiSynapticiilaLength of branchial regionLength of collarNot morethan 595Not morethan 61-25Up to 9116Not morethan 3•921^34TTO* See foot-note on p. i'Ao.

650 E. C. PUXXETT.vialdivensis procured was onl\- 80 mm. long. Maldivensis is also a more stunted form, itstotal length averaging about 18 times the collar length as against 23 times in laccadivensis.All of which considerations point to the fact that we are here dealing \\\i\\ two distinctthough closel}" related forms.Ptychodera flava, var. saxicola (PL XXXYIII. fig. 17 : PI. XXXIX. figs. 28, 30, 31PL XLIV. figs. 33—41).Locality, etc. Hulule, Maldive Is. Four specimens were obtained by breaking up adead coral mass on the sand-flat.External features. This is a relatively short stunted form. The length of thesmallest specimen when preserved was 32 mm., that of the largest 65 mm. The animal isthick in comparison with its length (PI. XXXYIII. fig. 17). The total length relative tothe collar as unity in the four specimens is 16-2, 12'8, 16"5, 16'3, giving an average ofrather less than 16, which is low in comparison with such forms as laccadivensis (see p. 664).The genital pleurae are large but the liver saccules are small and not lobulated. Neitheris there any differentiation into an anterior darker and a jiosterior lighter group.Ixterxal structure.Proboscis. The radial arrangement of the longitudinal muscles is almost as well-markedas in laccadivensis. The proboscis cavity is fairly spacious. Dorso-venti'al muscles in frontof the pericardium may or may not be present. The ventral j'l'oboscis septum reachesnearly to the tip of the stomochord. The dorsal muscular decussation in the anterior partof the proboscis is well-marked and a few ventral fibres may jjass fi-om it round the cavityof the proboscis. Paired proboscis pores are present of which one or both may be infunctional communication with the dorsal coelom. The racemose oi'gan is well-marked butdiffers considerably in size among the different specimens. It may shew a certain amountof lobulation.Collar. The ca^^.ty of the anterior part of the collar is spacious. The dorsal collarseptum in two cases shewed the usual condition, i.e. was complete after the 1st root. Inone case, however, it commenced about 'o mm. behind the 1st root, and in another a littlein front of it. The ventral collar septum is more marked than usual, being in three ofthe four specimens complete in the hinder part of the collai-.The nerve cord may shew a lumen continuous throughout or there may be a greateror less amount of occlusion. The number of dorsal roots varies from 2—4. In one specimena somewhat remarkable dorsal root occurred. It was of considerably larger size than usual(PL XXXIX. fig. 28) and was ob^dously formed by two distinct portions, viz. an outgrowthfrom the collar cord with a cap of yellowish brown pigment, and an epidermal ingrowthat the end of which was a large mass of mucus. The two portions of the root fused moreor less with one another. It is possible to regard such a structure as possessing somesensory significance, and to suggest that the mucous portion of the epidermal ingrowth mayact as a crude lens in focussing rays of light on the pigmented portion of dorsal outgrowthfrom the collar cord.The cornua of the nuchal skeleton vary greatly in length but are on the whole unusuallyshort.Trunk. One of the most conspicuous features of this variety is the small size of thebranclii;il region. Not only is the branchial jôrtion of the oesophagus very small compared

THE ENTEROPNEUSTA.G51with the ventral portion (PI. XLIV. fig. 38), but the length of the branchial region comparedwith that of the collar is exceedingly short. In none of the specimens is it more than aquarter as long again as the collar, whilst in two ca.ses it is even shorter than the latterstructure.The post-branchial groove however is well-developed, being on the average about one-thirdof the length of the branchial region.The number of synapticula is very variable. As many as nine or as few as three maybe present.The genital folds are large (PL XLIV. figs. 38, 39) in the branchial region and alsoin the region of the post-branchial groove (PI. XLIV. fig. 41). Just behind this regionthey rapidly diminish in size (PI. XLIV. fig. 40). In all four specimens the gonads arequite immature. Points of interest in connection with them are dealt with later (p. 661).An account of the pygochord is given on pi. 6.59.Ptychodera flava, var. gracilis (PL XXXVIL fig. 5; PL XXXVIII. figs. 10, 19; PL XLV.figs. 42, 44; PL XLVI. figs. 50, 53— .5.5).Locality, etc. Hulule, Maldive Is. From boulder zone under stones in sand. Alsofrom sand at ilinikoi in company with Pt. flava, var. laccadivensis.With reference to the specimens from Hulule Mr Stanley Gardiner has made thefollowing note :— " They are found sparingly under the stones of the boulder zone in thesand. A couple of specimens or more can almost invariably be obtained wherever a largegrey Actinian lives, the latter seeming to protect the Enteropneusts. Polychaets, Sipunculids,and Holothurians are not generally found in the same patch of sand."External features. This is a small variety, the longest specimen of which measured68 mm. after preservation, the shortest 32 mm. (see Table 12, p. G73). It is somewhat slenderlybuilt though the total length in comparison with that of the collar averages 19'6. Theposterior portion of the animal's body is usually very slender (cf. PL XXXVIL fig. 5) thoughthis is not so much the case in larger specimens. The liver saccules shew an anterior darkgroup and a more extensive posterior lighter group. The saccules are not large (PL XXXIX.fig. 19) and are as a rule not at all or but slightly lobulated except in the case of largespecimens (PL XXXIX. fig. 10, *). In the specimen from which the coloured sketch(PL XXXVIL fig. 5) was made all the liver saccules appear dark. It is possible that itis only after preservation that the darker anterior group can be separated from the rest.Internal structure.Proboscis. The musculature is rather feebly developed, the longitudinal fibres beinggathered into widely separated radial bundles as in laccadivensis (cf. PL XXXIX. fig. 25).The dorsal muscular decussation may be feebly developed or fairly strong. Dorso-ventr.ilproboscis muscles are present anterior to the pericardium. The ventral proboscis septum iswell-developed, reaching almost to the tip of the stomochord. Of the paired proboscis poresonly one is functional, placing the dorsal coelom in communication with the exterior. Thismay be either on the right or left side. The other pore is generally smaller and in onecase had disappeared altogether. The racemose organ is well-marked though unlobulated oronly faintly so.

652 R. C. PUNNETT.Collar. The musculature of the collar, like that of the proboscis, is somewhat feeblydeveloped. The cavity in the anterior part of the collar is very spacious. The intra-coUarlumen of the oesophagus is unusually large (PI. XLV. fig. 42). The dorsal collar septumis present as usual behind the first root. The ventral septum may be found at the hindend of the collar or it may be absent.Table 4.Pt. flava, var. gracilis.No. of specimen(1)(2)(3)(i)(5)Proboscis coelomFairly largeNot largeas (2)Spaciousas(l)Collar coelomSpaciousas(l)as (1)as(l)as(l)Ventral proboscis .septumNearly to tipof stomochordas (1)as (1)as(l)as (1)Dorso-ventral proboscis musclesPresentas (1)as(l)Dorsal collar septumComplete after1st rootas (1)as (1)as(l)as(l)Ventral collar septumTraces onlyas (1)Absentas (3)Complete athind end ofcollarRacemose ora;anWell markedbut small andunlobulatedWell marked.UnlobulatedWell marked.Slightlylobuhitedas(l)as (1)Dorsal proboscis muscle decussationFairly wellmarked. Noventral circularmusclesNot verymarked. Noventral circularmusclesWell marked.No ventral circularmusclesVery feeble.No ventral circularmusclesas(l)Dorsal roots*RRRRrRRRRRrRRrProboscis pores*1RLrIRIRL onlyNerve cordLength of post-branchial groove-Length of branchial regionLumen continuous•11as(l)•11as(l)•10as (1)•16as (1)•15Length of cornua x 100Length of collar17-419^0\vz14^1Circumference of branchialCircumference of asoph.ces.oes.1-26M41-00•60•85SynapticulaNot more than9Not more than7Not more than7Not more than7The collar cord exhibits a continuous lumen throughout. Three roots are usually tobe found. The cornua of the nuchal skeleton are rather shorter than usual, extending overabout I—i of the collar length.• See foot-note on p. 645.

THE ENTEROPNEUSTA. 653Trunk. The branchial region in this variety is very short, averaging only a quarteras much again as the collar length (see Table 12, p. 673). In the Maldive specimensthe branchial part of the oesophagus is at least as large and generally somewhat largerthan the ventral portion. In the Minikoi specimens on the other hand it is somewhatsmaller, a feature in which they appro.xiniate to laccadivensis. The post-branchial gi-oove isvery short in the specimens from Hulule, not being more than about -jL of the length ofthe short branchial region. In the Minikoi specimens it is rather longer. The genitalpleurae are large in the branchial region (PI. XLVI. figs. 50, 54). They diminish in sizeconsiderably in the region of the post-branchial groove (PI. XLVI. figs. 53, 55), after whichthey arevery small.The proportions of the various regions of the body in the above account have beendetermined from an examination of 28 specimens from Hulule (vide Table 12, p. 673).Five specimens only were procured from Minikoi and, as will be seen in Table 4, Nos. 4and 5, these differ somewhat from the Hulule forms. It is possible that e.xamination of alarger amount of material may shew that these Minikoi specimens belong to a distinct variety.The difference in their mode of occurrence (p. 651) would seem to point the same way,but in any case they are verj' closely related to the Hulule form.Ptychodera flava, var. muscula (PL XLII. fig. 18).Locality, etc. A Maldive form from Goifurfehendu Atoll, Goidu. It was obtained fromthe sandy shore to the east of the island in the sand below the weed and under somesquare slabs of beach sandstone. In company with it was found Spengelia porosa. Abouta dozen specimens procured inall.External features. Colour in life pale yellow with very black hepatic region. Asmall form with a total length after preservation of 31— 48 mm. Average length comparedwith collar as unity = 15'6. A somewhat short and stoutly built fonn, generally speaking.The anterior hepatic caeca are, after preservation, darker than the rest.Internal stbuctxjre.Proboscis. The internal longitudinal musculature is very strongly developed and closelysurrounds the central complex, almost obliterating the proboscis cavity. No dorso-ventralmuscles anterior to the pericardium. The ventral proboscis septum is short and does notreach nearly to the tip of the stomochord. Of the paired proboscis pores one may notbe functional. The racemose organ may be small or fairly well marked and slightly lobulated.The nuchal skeleton has a well-developed keel which gives off a flattened expansion overthe racemose organ. Such an expansion occurs generally in the genus but is not usuallj^so well-marked as in the present variety (PI. XLII. fig. 18). A strong dorsal musculardecussation occurs in the anterior portion of the proboscis, and from it pass some circularfibresventrally.Collar. The musculature of this region also is swell developed. The cavity in theanterior part of the proboscis is comparatively large. The dorsal septum is found as usualafter the firet root though it may not immediately be complete. The ventral septum isabsent or traces of it only are to be found.The lumen of the nerve cord shews a marked tendency to become occluded. Three orfour dorsal roots may be present.G. II. 84

654 R. C. PUNNETT.Table 5.Pt. flava, var. muscida. Pt. Jiava, var. cooperi. Pt. viridis.No. of specimen

THE ENTEROPNEUSTA. 655length.The cornua of the nuchal skeleton are short, extending over less than i of the collarTrunk. The branchial region is fairly long, averaging more than double the length ofthe collar in 10 specimens (see Table 12, p. 673). In one small specimen only was itless than double the length of the collar. On the whole it is remarkably constant in length.The branchial division of the cEsophagus is considerably less than the ventral portion. Thepost-branchial canal was found to be short in the specimen examined, being less than ^ ofthe length of the branchial region. The post-branchial pre-hepatic genital tract is comparativelyshort. The genital pleurae are well-develojied.Ptychodera flava, van cooperi (PL XXXVIII. fig. 12; PI. XLV. figs. 4.5—47).LOCALITV, ETC. Two specimens, both somewhat imperfect, from N. Male Atoll. Dredgedin 5 fathoms on a sandy bottom within the velu of Jaro near Helengeli.External features. A small form with a maximum breadth in the collar and branchialregion of less than 3 mm. Behind the hepatic region the diameter of the animal is onlya trifle over 1 mm. In the preserved specimens the collar and proboscis are both very short,their width being greater than their length (PL XXXVIII. fig. 12). The genital pleuraeare large in the branchial region, which is rather more than double the length of the collar.The genital region between the termination of the branchial and the commencement of thehepatic caeca is relatively long. The hepatic caeca are short but well-developed, and ontheir inner sides are lobulated. There is no distinction into lighter and darker ones.Internalstructure.Proboscis. The cavity of the proboscis is well-developed in one specimen, whilst inthe other it is small. The radial an-angement of the muscles is not so conspicuous as inmost members of the genus. Dorso-ventral muscles anterior to the pericardium are notpresent, and the ventral proboscis septum is very short. The right proboscis pore in eachcase places the dorsal coelom in communication with the exterior. The left pore is presentin one .specimen but absent in the other. The racemose organ is well-marked but unlobulated.The keel of the nuchal skeleton is somewhat larger than usually obtains in the species(PI. XLV. fig. 45). The skeleton is altogether massive (PL XLV. fig. 46).Collar. The cavity in the anterior part of the collar is very spacious. Posterior toit the collar musculature is unusually strongly developed, a fact which may in some measureaccount for the extreme shortening of this region on preservation. The dorsal septum isas usual complete after the first root. A ventral septum was completely absent in onespecimen though traces of it occurred at the extreme hind end of the collar in the other.In one case a single dorsal root reaching to the epidermis was found. In the secondspecimen this was supplemented by a rudimentary one. The lumen of the collar cord shewsa tendency to occlusion behind the level where the roots come otf.A noteworthy feature of this variety is the condition of the nuchal cornua which extendback to the hind end of the collar, the tip of them being found in sections which alsopass through the first branchial bars. Such a condition is most unusual amongst thePtychoderidae, recalling that recently described by Ritter ('OO, p. 113) for Harrimaniamaculosa.Trunk. The branchial portion of the oesophagus is rather larger than the ventral portion.Seven to eight synapticula are present. The post-branchial groove is large (PL XLV. fig. 47),84—2

656 R. C. PUNNETT.whilst the oesophagus at this level is very small. The genital pleurae are still large in thisregion but become much reduced shortly after it.Ptychodera viridis, n. sp. (PL XXX VII. figs. 2, 6, 7 ; PI. XXXIX. fig. 32; PI. XLII.figs. 17 and 19).Locality, etc. From Hulule, Maldive Is. Three specimens only, two being complete,were dug from sand towards the cast of the island.External features. Coloured sketches from life of this worm were fortunately madeby Mr Forster Cooper. From the reproductions of these on Plate XXXVII. it will be seenthat green is the prevailing tint on the body of the animal, though the j)roboscis is paleyellow, and the collar pale yellow with a certain amount of orange. To the predominantbody tint the animal owes its specific name. From the sketches it appears that the proboscisis considerably longer than the collar, a proportion which still exists in the preserved creature.The length is not great. Of the two complete specimens one measured 36 mm. and thesecond only 21 mm. in length after preservation (ratio of total length to collar length beingrespectively 18 : 1 and 14 : 1). Compared therefore with such forms as Pt. flava, var. laccadivensis,this sjjecies is a small, short, and somewhat stunted form. The genital pleuraeare well-developed. The external liver saccules are relatively feebly developed and are ofa uniform colour.Internal structure. The musculature of the proboscis is strong and compact, theradial bundles into which the longitudinal muscles are gathered being closely connected byconnective tissue. The powerful development of the longitudinal muscles leads to the practicalobliteration of the proboscis cavity (PI. XXXIX. fig. 32). A well-marked dorsal musculardecussation occurs in the anterior part of the proboscis (PI. XXXIX. fig. 32, dmd) andfibres from it pass ventral to the central complex. Dorso-ventral muscles anterior to thepericardium are not present. The ventral proboscis septum reaches forwards almost to thetip of the stomochord. The racemose organ is small and unlobulated. Both proboscis poresare present though only one is in functional communication with the dorsal proboscis coelom.This may be either the right or the left one.Collar. The musculature and the connective tissue are here strongly developed andthe cavity of the collar is very much reduced. The dorsal septum occurs after the firstroot as usual and is generally complete. Traces of the ventral septum may occur. Thelumen of the collar cord is almost entirely obliterated throughout and the cord in sectionhas as great a dorso-ventral diameter as a lateral one (PI. XLII. fig. 19). In one of thespecimens sectioned three roots were present of which the last was rudimentary.The cornua of the nuchal skeleton apparently vary much in length. In one specimenthey extended over about ^ of the collar, whilst in another they were rather more than aquarter as long as this structure.Trunk. The branchial region is short. Compared to the collar length as unity itmeasured in the three available specimens -85, I'OO, and 1-44, giving an average of 110.The branchial portion of the oesophagus is approximately of the same size as the ventralportion. The post-branchial groove is very ^hort and insignificant. The genital folds arelarge in the branchial region and also in the region of the post-branchial groove (PL XLII.fig. 17).

THE ENTEROPNEUSTA. 657Ptychodera asymmetrica, n. sp. (PL XXXVII. figs. 1 and 9; PI. XLVI. figs. 52, 56, 58).Locality, etc. From Hulule. According to Mr Stanley Gardiner, " Near the south isletis a pool with loose rocks well within the boulder zone. This form was found here inaccumulations of sand under stones. They are remarkable in life for the enormous quantityof mucus they secrete, so much indeed that it is almost impossible to obtain them cleanfor preservation." About 10 specimens were procured, mostly somewhat fragmentary.External features. A small form measuring on the average about 40 mm. in length(PL XXXVII. fig. 1). One larger specimen, a sketch of which was made by Mr ForsterCooper and is reproduced on PL XXXVII. fig. 9, measured after preservation 60 mm. inlength with a collar 3 mm. long. This specimen however was unusually large. Two pointsabout its external appearance merit attention. In the first place the liver saccules aresomewhat small and uniformly dark in colour. There is no sharp line of demarcation betweenan anterior set of very dark caeca and a posterior set of lighter ones as in Pt. Jiava, var.laccadivensis. In the second place careful examination shews that the left genital pleura isalways somewhat larger and more swollen than the right one. In all the eight specimensexamined by me the gonads shew asymmetry by being developed only on the left side.This was the case both in a very young specimen with quite immature gonads, and alsoin the large specimen above alluded to in which the gonads were full of ripe spermatozoa.In his account of Pt. flava Willey ('99, p. 240) mentions a case in which the gonadswere only developed in the right genital pleura, those in the left being apparently in astate of an-ested development. Evidently with the case of Asyminetron in his mind Willeywrites, " Such a differential behaviour of the two sides of the body is of interest as indicatinga tendency to unilaterality in the matter of the gonads." Spengel ('03, p. 305) criticisesthis remark of Willey's, regarding such a condition as produced by the presence of aparasitic copepod, Ive sp. In the two cases examined by Spengel where the gonads of oneside were undeveloped the parasite occurred in the genital pleura of that side, and thereseems little doubt that Spengel's explanation is here correct, and that the condition is apathological one. But there can be no doubt that this explanation will not hold for Pt.asymmetrica. The fact that in eight cases, in different stages of growth, gonads were alwaysabsent from the right pleura, coupled with tlie fact that no parasite was to be found,seems to shew beyond all question that unilaterality of the gonads is a feature which ischaracteristic of this species.Internal structure.Proboscis. The longitudinal muscles do not exhibit a markedly radial arrangement ofbundles. They are strongly developed and almost entirely fill the cavity of the proboscisso that there is no space, or only a very small one, between them and the central complex.There are no dorso- ventral muscles in front of the pericardium. The ventral proboscis sepituradoes not reach to the tip of the stomochord and is often much shorter.The racemose organ is subject to considerable variation. It may be small and unlobulated,large and lobulated or not.There is usually a well-marked dorsal muscular decussation in the anterior part of theproboscis though no circular fibres pass from it ventrally.Collar. The cavity of the collar varies considerably. It is on the whole not largeand may be almost absent. The collar musculature is well-developed. The dorsal septum

658 R. C. PUNNETT.is always complete after the first root. The ventral septum is a more conspicuous structurein this species than in most others of the genus. It is always found in the posterior partof the collar and may reach forwards over ^ of the collar length.Table 6.Pt.asymmetrica.No. of specimen(1)(2)(3)(4)(5)Proboscis ooelomVery smallas (1)Well markedbut smallas(l)Obliterated bymusclesCollar coelomMuch reducedAlmostobliteratedFairly spaciousVery smallWell markedVentral proboscis septumShort. Notnearly to tip ofstomochordNot to tip ofstomochordNot quite totip ofstomochordas (3)as(l)Dorso-ventral proboscis musclesAbsentas(l)as(l)as(l)as (1)Dorsal collar septumComplete after1st rootas(l)as (1)as(l)as(l)Ventral collar septumComplete inhind end ofcollaras (1)as(l)as(l)Complete inposterior ^ ofcollarRacemose organLarge butunlobulatedLarge andlobulatedas (1)Small andunlobulatedVery large andlobulatedDorsal proboscis muscle decussationWell marked.No ventral circularmusclesas(l)as(l)Not wellmarked. Noventral circularmusclesas(l)Dorsal roots*RRRRRrrRRRRRProboscis pores*LRLrIRIRIRNerve cordLength of post-branchial grooveLength of branchial regionLumen almostobliterated•23Lumen distinctin placesLumen distinctin places.Strong tendencyto obliteration•18as(l)•24as (1)Length of cornua x 100Length of collar24-520-947-340^52b-'Circumference of branchial oes.Circumference of ocsoph.oes.1-081-041-06Synapticula,Not more than 5The lumen of the collar cord is never continuous throughout. It may be present asa number of small cavities much broken up, or it may be practically absent, the cord shewing* See foot-note ou p. 64.5.

THE ENTEROPNEUSTA. 659only the merest traces of a lumen. As is often the case with the collar cord, when thelumen shews a marked tendency to occlusion, the dorso-ventral diameter as seen in transversesection tends to become relatively gi-eat as compared with the transverse diameter (PI. XLIV.fig. 29). The number of the dorsal mots is xrvy variable There may be as few as one,though four seems to be the maximum.The cornua of the nuchal skeletim arc cm the wlicile loiitr for memlxTs of this c-eniisbut shew a considerable amount of variation. 'J'hey may extend (jver only \ of the collarlength, or their length may be ecjual nearl}- to ^ that of the c(.)llai-.Trunk. The branchial jjortion (if the oesophagus is of about the same size as theventral part. The relative length ol' the branchial region as compared with the collar lengthis short, it being seldom more than half as long again as the latter and sometimes evenless. In the large specimen figured on PL XXXVII. fig. !J, however, it was rather morethan three times the collar length.The post-branchial gi-oove on the other hand is longer than usual, averaging betweeni and I the length of the branchial region.The genital folds are somewhat small (PL XLVI. figs. .52 and .5(J) and become mereridges in the region of the post-branchial groove (PI. XLVI. fig. 58).SOME ANATOMICAL POINTS.As Spengel in his latest publication ('03) differs on one or two jxiints fnjni Willeyit may be worth devoting a few lines to them. In two of these cases, the pygochord andthe lateral septa, I find myself in agreement with Spengel rather than Willey.The pygochord is a structure on which Willey has laid some stress, describing it as"a longitudinal, s(jlid, supporting band" ('99, p. 248), and evidently seeing in it a skeletalstructure for the support of the caudal region. On the ground of its minute proportionsSpengel ('03, p. 317) dissents from Willey's interpretation, and one cannot help agreeingwith Spengel in refusing to regard such a small and rudimentary structui'e as of anyimportance from this jwint of view. As Spengel remarks we have absolutely no knowledgeof the function (,)f this apparently vestigial structure, and it is with some diffidence thatI venture to suggest that it may be the remains of a ventral si])hon which was at onetime of functional impoi'tance but now vestigial. The occuirence of such a sii)hon, whatevermay be its exact function, is common among sand-feeding animals. Similar structures occur inthe Echinoidea, in the Capitellidae, and in certain Chaetopoda such as Thallasema and Echiurus— all creatures which derive their nutriment fi'om among the large quantities of sand continuallypassing through the alimentary canal. The conditi

660 R. C. PUNNETT.Lastly there is a point in connection with the branchiae which calls for short notice.It has been assumed that the main function subserved by these structures is that ofrespiration, and in the figures given by most authors the blood vessels form a prominentfeature. Nevertheless the course of the branchial circulation is a point which has neverbeen satisfactorily cleared up (cf. Delage and Herouard, '98, p. 41), and in looking throughnumerous series of sections through the branchial region I have been struck by the infrequencywith which one finds any blood in these structures. On the other hand the .sub-epidermalvascular plexus is exceedingly well-developed everywhere and it is difficult to avoid theconclusion that respiration is mainly, if not entirely, carried out by the large skin area, whilstthe main function of the gills is to act as a sieve for straining off the water from themixture of sand and water continvally swallowed by the animal.THE FORMATION OF THE GONADS.The origin of the gonads is a subject on which widely diverse views have been upheldby different observers. Bateson ('86) attributed to them an ectodermal origin, Spengel ('95)regards them as being developed in a blood space, whilst Morgan ('94, p. 60) holds that theyare formed from the mesodermal elements of the coelom. The question is one of considerabledifficulty and none of the above observers has made out a very strong case in support ofhis view. Bateson bases his belief on the early connection apparent between the gonad andthe ectoderm ('86, PI. XXXII. fig. 110). Spengel considers this connection to be due tothe precocious formation of a duct and claims to have found sex cells at a very earlystage of development inside the blood vessels ('95, PI. II. figs. 27 and 28). He findsadditional support for his view in the fact that in a small specimen' of Pt flava, var.laysanica, the "Anlage" of the gonad first appears between the two lamellae of the lateralseptum ('03, p. 302). The case which he has made out is far from convincing since itis by no means certain that the small cells which he regards as primitive sexual cells areof that nature, whilst on the other hand there are good grounds for looking upon thelateral septum as composed of four rather than of two lamellae (see below, p. 661). LastlyMorgan's contention as to the mesodermal origin of the gonads is not borne out by hisfigures. In the earliest stage figured by him ('94, PI. VI. fig. 79) the gonad is obviouslyin continuity with the ectoderm, a connection which, to judge by his figures, is very soonlost, though doubtless re-established later on the formation of the genital ducts. The questionof the ectodermal origin of the gonads turns largely upon the interpretation of the ectodermalconnection found at different stages of their development. In other words, has thegonad an ectodermal connection at two different stages of its growth, the earlier representingthe ingrowth of ectoderm to form the gonad, whilst the latter represents the functionalduct ? From the following observations on Pt. flava I am inclined to believe that such isthe case. As the gonads appear to develop earlier in some varieties than in others I haveconsidered them apart with the following results.(1) Var. laccadivensis. The youngest stages of the gonads were met with in a verysmall specimen about 15 mm. long. The young gonads are in many places in connectionwith the ectoderm (PI. XL. fig. 36). In the region of the genital pleurae this connection' Judging from the regenerated material at my disposal in doubt iu considering this small specimen of Speugel's to be athe case of Pt. flava, var. laccadivensis, I have very little regenerated one.

THE ENTEROPNEUSTA. 661is almost invariably found where the lateral septum joins the basement-membrane at thetip of the pleura. Occasionally an ingrowth from the ectoderm of the inner surface of thepleura is to be seen, but this is rare. The irregular occurrence of the ectodermal connectionsand their somewhat attenuated condition seems to indicate that they are in process ofdisappearance. And this supposition is borne out by the fact that in somewhat olderspecimens the gonads are devoid of an}- ectodermal connection.(2) Var. sa.vicola. Though all the specimens of this variety were of fail- size the gonadsin all are in a very backward state of development. The gonads are in all cases youngand in all cases possess a more or less well-marked ectodermal connection. This connectionis relatively wider in the }-ounger gonads (cf. PI. XL. figs. 41 and 42). A still youngerstage of an ectodermal ingrowth at the tip of a genital pleura is shewn on PI. XXXIX.fig. 31. There can be little question but that this is of the nature of an ingrowth, andindeed rounded cells may be seen in it, which are not to be found in other parts of theectoderm, and which are probably to be regarded as primitive genital cells. The mainingrowth is that at the tip of the pleura as in var. laccadivensin, but the accessory ingrowthson the inner surface of the pleurae are mvxch more numerous in saxicola, a fact probablycon-elated with the larger size attained by the animal for a similar stage of gonidial development.Unfortunately none of the four specimens of this variety possessed older gonads.(3) Var. inuscula. In a specimen with immature and somewhat small gonads an ectodermalconnection is generally wanting. It may be present here and there. In an olderspecimen in which spermatocytes could be recognized in the gonads (PI. XL. fig. 37) theectodermal connections are present on almost all the gonads.(4) Var. maldivensis. This variety is characterized by often having long slender genitalducts. The}' are found connected with tairl}- well-developed gonads and in some cases Ihave been able to make out their double origin, in part from an ectodermal ingrowth andin part from an outgrowth from the gonad. In one or two instances the two portions hadnot eflPected a junction, a condition sujjporting the view that the true genital ducts arelate in making their appearance. It has already been noticed that the ectodermal ingrowthsnear the tijj of the pleurae always occur directly over the point where the lateral septumjoins the basement-membrane and pass down between its lamellae. On the other hand theducts in connection with the gonads nearest the tip of the pleurae may be entirely independentof the lateral septum (PI. XXXIX. fig. 27).All the above observations are in harmony with the view that the gonads are (inPt. flava at any rate) derived from ectodermal ingrowths, that they subsequently lose theirconnection with the ectoderm, but regain it later when the genital ducts are established.Further, on this view we can explain the latei-al septum of the Ptychoderidae, regarding itas having in the first place been brought about by the basement-membrane being carriedin by the primitive ectodermal ingi-owths at the tip of the pleurae (at that time probablyvery much smaller). On this view the lateral septum should be four-layered since thebasement-membrane consists already of two layers enclosing blood spaces. That four potentiallayers are present is shewn b}' the fiict that the apparently single layer round the gonadis in reality a double one since blood spaces frequently occur in it (PI. XL. fig. 41). Theca\'ity of the gonad is therefore quite distinct from the blood spaces, which militates againstSpengel's view of the nature of the gonad.The gonads of Ptychodera jJava are characterized by the jjresence of peculiar bodiesG. II. 85

662 R. C. PUNNETT.apparently devoid both of structure and of nucleus. The origin of these bodies, the " fettartigKiigelchen" of .Spengel and the "eosinophil globules" of Willey, is somewhat obscure. Willeyholds that they are the products of nuclear degeneration accompanied by hypertniphy of thenucleolus. Spengel ('03, p. 306) refuses to believe that they are the outcome of degenerativechanges. In the young specimen of Pt. laccadivensis referred to above I have beenable to follow what seems to be the history of these bodies. Certain of the spindle-shapedmesodermal cells become first oval and then more or less spherical in shape (PI. XL.fig. 38, o b), at the same time increasing slightly in bulk. A few granules make theirappearance in the hitherto clear cytoplasm. A little later these cells appear to collecttogether in clusters of about 6—10 (fig. 38, c), which subsequently fuse together to formgiant cells packed with granules and with the nuclei degenerating (fig. 38, d and e). Laterthe nuclei disappear and the giant cells apply themselves close to the gonad. Where thisoccurs the wall of the gonad seems to break down and by some method which is not clearthe nutriment stored in the giant cells is transferred to the interior of the gonad whereit loses its granular appearance (cf. PI. XL. fig. 37). At later stages small round corpusclesof an eosinophil nature also make their appearance in the mesoderm and subsequently applythemselves to the gonads in a similar manner (PI. XL. fig. 41). The chief interest of theprocess seems to lie in the fact that although the sexual cells themselves are derived fi-omthe ectoderm', it is the mesoderm which provides them with nourishment and which contributesthe yolk to the eggs.The above account is of interest when it is considered with reference to our conceptionof the nature and properties of the coelom. According to present ideas one i>f the chieffunctions of the coelom is to give rise to the generative cells from the epithelium whichlines it. Further it is usually held that the most primitive method of formation of thecoelom is that of archenteric diverticula. In animals like the Enteropneusta, where thismethod of the formation is found, we should naturally look for genital cells arising fromits lining. That this is not so may cause us to regard with some reservation the statementthat the coelom was originally a gonocoel-, and to consider it rather as an organ specialized,among other things, for the reception and maturation of the genital cells.VARIATION IN PTYCHODERA FLAVA.The different varieties of Pt. Jiava are by no means easy to distinguish from one anotherafter preservation. An adequate examination of the characters which are of systematic valueinvolves the preparation of a large number of serial sections. If a trustworthy criterion basedupon external features alone could be found much labour might be spared the Enteropneusticsystematist. The large amount of material collected by Mr Stanley Gardiner has enabledme to attempt this.The characters upon which such a criterion might be based must satisfy two conditions;(1) they must be capable of easy measurement, and (2) they must be independent of the'In this connection it is interesting to notice that so long figs. 88 and 89).ago as 1885 Hubrecht described the ectodermal origin of the - For the most recent general account of the coelom thegonads in the Nemertean Linens gesferensU. He was able reader may be referred to Lankester's Treatise on Zoology,here to distinguish with certainty the primary ectodermal IttOO, Pt. n. chap. ii.connection from the later formed duct (Hubrecht, '8S, PI. v.

THE ENTEROPNEUSTA. 663gro\vth of the animal. This latter condition precludes the direct use of absolute measurements.It is obvious that a ratio must be made use of—a simple ratio whose two factors areequally affected by growth changes. Though several distinct regions may be distinguishedin the body of a Ptychodera, with the exception of the collar and branchial region, theirlimits are not very clearly defined. Accordingly most attention has been paid to the ratioof branchial to collar length. And this more especially since any collection of Enteropneustswill be largely made up of damaged specimens, and though few specimens may attain toanything like completeness, yet in the gi-eat majority both collar and branchial regions willbe perfect. Great accuracy in the measurement of such animals as the Enteropneusta isout of the question since in a soft-bodied creature relative differences in the state ofcontraction of the various body regions may easily occur, whilst the personal equation mustenter largely into the result. In the present instance however all the material had beentreated in the same way, i.e. had been nai'cotised in chloral hydrate for several hours beforepreservation, thus ensuring an equable contraction, whilst the personal equation was as faras possible eliminated by my making all the measurements within the space of a week or so.By i-AV the most frequent of the varieties described in this paper is laccadivensis, andit is here that the measurements are most complete. In addition to the length of thecollar and of the branchial region the total length and the length of the genito-hepaticregions was measured wherever the specimen was sufficiently perfect. The width of thecollar was also registered. The results for 123 specimens (fewer in the case of the genitohepaticand total lengths) are given in Table 11, pp. 671— 2, and in the diagram on p. 666.Before however anj- value can be attached to these figures it must be shewn how, if atall, growth affects these ratios.The method employed for estimating growth changes was to divide the animals intoseveral groups according to size, and to calculate the above three ratios for each groupseparately. As the collar width was sometimes less, sometimes greater, than the length itwas thought advisable to take this factor also into account, and in the case of laccadivensisthe following groups were made.Group 1. Collar length x breadth not > 16„ 2. „ „ X „ > 16, but not > 25.„ 3. „ „ X „ >25, „ „ >36.„ 4. „ „ X „ >36

664 R. C. PUNXETT.— '^^S*-!^^- Mean for Group 1 = 4-94 38Collar lengthNo. of Specimens„ „ „ 2 = 4-90 33„ „ „ 3 = 4-84 15Average 4'90Totan^|^_ Mean for Group 1 = 23-1 19Collarlength„ „ „ 2 = 22-4 17„ „ „ 3 = 23-4 13Average 22-9An examination of the above table brings out clearly the important fact that two ofthe three ratios, i.e. those of the genito-hepatic and total lengths, are quite unaffected bygrowth changes, whilst that of the branchial region is not greatly affected. Neglectinggroup 4 in which there are so few specimens there is a gradual rise in the ratio withincrease in size from 2*08 in group 1 to 2-18 in group 2, and 2-36 in gi-oup 3. There istherefore an increase of about 12 7o in group 3 as compared with group 1, an increasesufficiently well-marked though not very great when we take into account the unavoidableroughness of the measurements. A possible source of error must be noticed here. A considerablenumber of specimens (some 8—10 7o) were regenerating. Where this process wasobviously at work the specimens were not included in the above measurements. In thelatest stages, however, regenerated individuals are impossible to distinguish from ordinaryones with a somewhat shorter branchial region than usual. As regeneration is far morecommon in the smaller specimens it seems almost certain that the values of the ratio forgroups 1 and 2 are somewhat too low in comparison with those of gi-oup 3. On the wholeit would appear from these measurements on laccadivensis that the proportions of the bodyof this Enteropneust are very little, if at all, liable to alteration during the later stagesofgrowth.This conclusion is borne out by a similar series of measiirements made on Pt. Jiava,var. maldivensis. The 52 specimens of this variety were divided into three groups of whichthe last contained only the five largest specimens (see Table 13, p. 674). On taking themean for the three ratios in each group the following figures were obtained.Branchial lengthCollar lengthGenito-hepatic lengthyCollar lengthTotal lengthCollar lengthTable 7.No. of Specimensêan for Group 1 = 1-65 19„ „ „ 2 = 1-62 28„ „ „ 3 = 2-00 5Average 1-67^^^^^^ ^^^ ^ ^ ^.^^ jg„ „ „ 2 = 4-14 28„ „ „ 3 = 5'23 5Average 4 -41Mean for Group 1 = 16-5 6„ „ „ 2 = 18-7 9„ „ „ 3 = 17-6 2Average 17-7

THE ENTEROPXEUSTA. 665There is more irregularity here in the figures for the genito-hepatic length and totallength, which perhaps is only to be expected in view of the smaller number of specimens.There is however no uniformity indicating a gi-owth change. The value for group 3 in thebranchial series is far larger than f(5i' groups 1 and 2. This however is due to the largebranchial region of a single specimen (Table 13, No. 49) and its effect on the few individualsof group 3. The closeness of the figures for gi-oups 1 and 2 (I'GS to 1-62), where thereare more specimens available, points to the ratio of branchial length to collar not beingaffected by gi-owth changes. Assuming then, and the assumption seems a fair one, thatgrowth has little or no effect on the relative proportions of the body in Ptychodera we havebefore us an easily applied criterion for distinguishing different positions of organic stabilityin this genus. We have but to determine one of these ratios (and in practice the branchialone will be found the most convenient) on a number of specimens of each supposed variety,and to apply to the series so obtained the ordinary biometric methods for measuring thevariability. Marked differences occurring in two groups of specimens would at once cast adoubt on the identity of two such groups.This method has been adopted here for such of the varieties as possessed nine or morespecimens. The branchial ratio alone was used owing to the fragmentary condition of mostof the individuals in each variety. On working out the mean and standard deviation ineach case the following results were obtained :Table 8.'

666 R. C. PUNNETT.-Scr.— tu« HJ= -°5C.5 -^

THE ENTEROPXEUSTA. 667In fact from these figures one may affirm with some confidence that laccadivensis andmuscula (though they cannot be separated from one another by this criterion) are quiteseparate from maldivensis, gracilis, and parva, whilst of the last three gracilis is veryprobably distinct fi'om the other two. By this criterion alone it is not possible to separatemaldivensis from parva any more than laccadivensis from miisctda. No doubt this could bedone in the case of these forms if the material were sufficient to treat another ratio (e.g.the length ratio) in the same way.The total length ratio was worked out for laccadivensis and maldivensis, in which formsalone the amount of material rendered the attempt feasible. As there are no definite segmentsby which to reckon, the absolute value obtained for a will depend upon the number of groupsinto which the material is broken up. In this case the mean in the two varieties is 23'1 and17"9 respectively. The series have been broken up into groups separated by an interval oftwo units, which is approximately 10 °/^ of the mean in each case. The treatment has beenuniform in each case and the results are as follows :Table 9.

668 E. C. PUNNETT.I ha\-e therefore estimated the variability of three separate regions of the body in Pt.laccadivensis, viz. the branchial region, the genito-hepatic region, reaching from the hind endof the branchial region to the point of junction of light and dark hepatic caeca, and thehepatic-caudal, extending from this point of junction to the anus. In the following tablethis is expressed quantitatively when the unit of variation' selected was the same in allthree cases, i.e. collar length x 1.Table 10.

THE ENTEROPNEUSTA. 669usually correspond fairly closely (cf. Willey, '99, PI. XXVI. fig. 1, and Spengel, '03,PI. XXIV. fig. 8). With regard to the second part of the question it may be easily demonstratedthat in a given stretch of body length the branchiae are more numerous than arethe epidermal annulations or the hepatic caeca in a stretch of the same length in thepost-branchial region. The number of tongue bars averages about 5-6 per mm. of length(see Table 14, p. 675). On the other hand the number of epidermal animlations in thepost-hepatic region is about I'O per mm. Therefore if we look upon these repeated partsas evidences of a rudimentary segmentation', we must regard the post-branchial segments(or at least those of the hepatic caudal region) as being on the average 3"5 times as longas the branchial segments. In other words the branchial segments are three times asnumerous as the hepatic-caudal ones per unit of length. Consequently if we calculate thecoefficients of variation on the basis of "segments" instead of collar length units we mustmultiply the coefficient of variation for hepatic-caudal region by 3"5 in order to compareit directly with that for the branchial region. This brings it up to the value 41'26 ascompared with 29'66 for the branchial region. If therefore we regard the Enteropneusts asexhibiting a rudimentary form of segmentation the variability in the different body regionsfalls into line with that of the Holochorda". Much phylogenetic stress however must not belaid upon this point since it is not improbable that the phenomenon of cephalization maybe shewn to be widespread among the Invertebrates also. What is of more importance isthe influence, small though it be, which the occun-ence in the Enteropneusta of a form ofsegmentation, similar in kind though less mai'ked, may exert upon our conception of themanner in which the merisni of the Vertebrata niaj- have arisen. And here a few remarksof a more speculative nature may not be irrelevant in connection withMETAMERISM INTHE ENTEROPNEUSTA.Willey ('99, p. 303) has recently made a brilliant suggestion with regard to the originof gill clefts. The discovery of the peculiar dermal pits of Spengelia has led him to regardgill-slits as having originally arisen as perforations in the interannular grooves formed forthe aeration of the gonads, a function which they eventually gave up for that of respirationon the establishment of an elaborate vascular system. In this way Willey establishes aconnection between the segmentation of the gills and of the epidermal annulations, theconnecting link being the gonads. It has seemed to me possible to extend this conceptionof Willey's and to see in the gonads and their arrangement the prime factor in thesegmentation of the chordata. We may take as our starting-point a small Triploblastic(and perhaps also Tricoelijmate) creature with three more or less definite body regions, ofnot widel}' unequal length, and of which the hindermost contains the gonads. The reproductiveelements would be small and fertilization external in the sea. Under these conditionsit is ob\'ious that, other things being equal, those with the largest gonads would have thebest chance of leaving offspring to peiijetuate and amplify this feature. Increased size of' Spengel ('03, p. 276 seq.) disagrees with Willey's view = It is interesting to notice that in Ptijchodera the differofthe significance of the epidermal annulations and sees in ence between variability in the different regions of the bodythem only the effects of muscular contraction on the dis- is not nearly so marked as in Aynpltio.rus where we mayposition of the epidermal glands. He points out that there regard the cephalization process as having extended further,exists a certain amount of irregularity. Such irregularity I have found the following values for C.V. in different regionshowever seems to me in no way to militate against the of the latter genus. Preatrioporal segments, €.¥. = ! '792;view of the significance of these structures taken by Willey. postatrioporal preaual, C.V. =2-655; postanal, C.V. =6'18.5.G. H. 86

670 K. C. PUNNETT.gonad spells increased bulk and in the absence of a specialized vascular system this increaseof bulk must be almost entirely dependent on increased length. For respiration would dependon transepidermal diffusion, a process which would more readily occur in a long slenderanimal than in a short thick one. This great elongation of the gonad would necessitatethe establishment of accessory ducts by which its products could readily and rapidly escape.From this it is but a short step to the stage of a series of independent gonads each withits own duct extending throughout the elongated trunk region—a condition physiologicallycomparable to that now found among the Nemerteans. Increase of bulk will still meanincreased fertility and such individuals will be fovoured by Genetic Selection\ provided alwaysthat the means for ensuring due aeration are adequate, whence we come to the establishmentof dermal pits for the aeration of the gonads. Later the pits become perforated and nodoubt these perforations supplied a physiological need and filtered off the excess of waterfrom the sand passing through the animal's alimentary canal. Probably it was somewherenear this phylogenetic ejaoch that the ancestral Enteropneusts took to an arenicolous life.The problem of extraction of nutriment from a relatively enormous mass of innutritionssubstance resulted in the specialization of the middle and hinder part of the digestive tract,and the establishment of the hepatic caeca led to the disappearance of the gonads in thisregion. They have left traces of their former presence in the epidermal annulations whichshew some tendency to irregularity now that their determining cause has disappeared; theyare still found in a rudimentary state in the hepatic region of some forms, but increasedphysiological specialization has on the whole led to their confinement to the more anteriorportions of the trunk.BIBLIOGRAPHY.'86. Bateson, W. " Development of Balanoglossm Kovalevskii," Quart. Journ. Mic. Sc.Vol.XXVI.'98. Delage and Herouard. Traite de Zoologie Concrete, Vol. viii. Les Procorde's.'94. Hill, J. P. " On a new .species of Enteropneusta from the coast of New SouthWales," Proc. Linn. Soc. N.S.W. Vol. x.'98. Hill, J. P. "The Enteropneusta of Funafuti," Memoirs Au-'it. Mas. in.'85. HuBRECHT, A. A. W. Proeve eener ontwikkelingsgeschiedenis van Linens obscurus. Utrecht.'02. KuwANO, H. " On a new Enteropneust from Misaki, Balanoglossus misakiensis, n. sp."Annot. Zool. Jap. Vol. IV.'94. Morgan, T. H. "The Development o{ Balanoglossus," Journ. Morph.'OO. RiTTER, W. E. "Harriinania maculosa," Proc. Wash. Acad. Sc. Vol. ii.'02. RiTTEK, \V. E. " The movements of the Enteropneusta," Biol. Bull. Vol. ill.'93. Spengel, J. W. "Die Enteropneusten," Naples Monograph.'Ol. Spengel, J. W. "Die Benennung der Enteropneusten-Gattungen," Zool. Jahr. Vol. xv.Syst.Abt.'03. Spengel, J. W. " Neue Beitrage zur Kenntniss der Enteropneusten," Zool. Jahr.Vol. xviii. Anat. Abt.'99. Willey, a. "Enteropneusta from the South Pacific, etc.," Willey's Zoological Results,Pt. 3.1Cf. Pearson, K., The Grammar of ScU'iicn. 1900, p. 437, and also The Chances of Death, etc., 1897, Vol. i. p. C3(Eseaj on Reproductive Selection).

THE ENTEROPNEUSTA. 671Table 11.Pt. flava, var. laccadivensis.§a'a

672 R. C. PUNNETT.Table 11(continued).a.ayVCOd

THE ENTEROPNEUSTA. 673Table 12.Pt. Jiaua, var. muscula. Pt. Jiava, var. gracilis.1p.CG"oo"Z

674 R. C. PUNNETT.Table 13.Pt. flava, VAT. maldivensis.as*5

THE ENTEROPNEUSTA. 675Table 14.Pt. J{ava;.,\'a,i.laccadivensis.No. oftongue barsAverage

676 R. C. PUNNETT.nlc.

THE ENTEROPNEUSTA. 677Fig. 17. Pt. flava, var. saxicola. Dorsal view, slightly enlarged.Fig. 18. Balanoglossus parvuliis. Anterior end from dorsal surface, x 6.Fig. 19. Pt. Jlava, var. gracilis. Preserved specimen from Minikoi. x 3.Fig. 20. Pt. Jlava, var. parva. Section through collar cord. The dorsal and ventral walls of thecentral lumen shew a tendency to stick together, x 85.Fig. 21. Pt. flava, var. parva. Section similar to above but from another specimen. The centrallumen shews a marked tendency to occlusion and the lateral gland cells (gl.) are stronglydeveloped, x 85.Fig. 22. Balanoglossus parvulus. Section through proboscis pore, x 45.Fig. 23. Willeyia bisulcata. Section through collar cord, x 85.PLATE XXXIX.Fig. 24. Balanoglossus parv7ilus. Section through collar, x 45.Fig. 25. Pt. Jlava, var. laccadivensis. Section through proboscis, x 45.Fig. 26. Pt. Jlava, var. parva. Section through anterior collar region, x 20.Fig. 27. Pt. flava, var. maldivensis. Section through edge of left genital pleura, x 85.Fig. 28. Pt. flava, var. saxicola. Unusual dorsal root formed by pigmented outgrowth from collarcord and glandular ingrowth from epidermis. These two portions fuse a few sections furtherback. X 85.Fig. 29. Willeyia bisulcata. Section through proboscis towards its hinder end. The dorso-ventralmuscles (nidv.) are seen converging to the minute vermiform process of the stomochord. x 45.Fig. 30. Pt. flava, var. saxicola. Small portion of inner surface of genital pleura shewing ingrowthfrom epidermis forming gonad, x 110.Fig. 31. Pt. flava, var. saxicola. Section tiirough tip of a genital pleura shewing epidermal ingrowthforming gonad, x 180.Fig. 32. Pt. viridis. Section through proboscis, x 20.PLATE XL.Fig. 33. Pt. flava, var. parva. An immature gonad shewing ectodermal connection, and quantityof mucus inside, x 180.Fig. 34. Spengelia nuddivensis. Section through collar canal just anterior to its opening into thefirst gill pouch. Ventral to it is tlie blind diverticulum of the first gill pouch of which theinternal opening is marked by an asterisk *. x 85.Fig. 35. Pt. flava, var. parva. An immature gonad in which the ectodermal connection is occludedby a mucous plug, x 180.Fig. 36. Pt. flava, var. laccadivensis. From young specimen (anterior hepatic region) shewing veryyoung gonad connected with the ectoderm, x 410.G. II. 87

678 R. C. PUNNETT.Pig. 37. Ft. flava, var. muscula. A nearly ripe c? gonad breaking through to the ectoderm.X 180. (sp = spermatocytes.) From an iron haeniatoxylin preparation.Fig. 38. Pt. Jlava, var. laccadivensis. From young specimen, a— e represent stages in the formationof the giant nutritive cells. All x 520.Fig. 39. Pi. Jlava, var. laccadivensis. Young gonad, shewing cavity formed inside, and outer coatof nutritive cells forming a kind of follicle. The membrane surrounding the gonad derivedfrom the lateral septum is still intact, x 410.Fig. 40. Pt. Jlava, var. laccadivensis. Young gonad, slightly older than in preceding figure. Themembrane surrounding the gonad tends to break down in places, x 410.Fig. 41. Pt. Jlava, var. saxicola. Section through young gonad with ectodermal connection. At thebase of the gonad the membrane is deficient permitting the invasion of nutritive cells, x 180.Fig. 42. Pt. Jlava, var. saxicola. Gonads somewhat older than in preceding figure, x 110.PLATE XLI.Fig. 1. Balanoglossus parvulus. Section through branchial region, x 45.Fig. 2. £. parvidus. Through region of post-branchial groove, x 45.Fig. 3. B. panndus. Through nuchal skeleton in anterior region of collar, x 45.Fig. 4. B. parvulus. Through post-branchial genital region, x 45.Fig. 5. Spengelia porosa. Through hepatic region. On the right the section has gone throughthe middle of a hepatic caecum, x 12.Fig. 6. Sp. maldivensis. Section through nuchal skeleton in the region of the keel {nh.). Theperihaemal cavity {ph.) of the right side is seen at this level. That of the left side doesnot reach so far forwards, x 45.Fig. 7. Sp. porosa. Section through the intestinal region behind the hepatic caeca, x 12.Fig. 8. 6)j. maldivensis. Schematic longitudinal sagittal section reconstructed from transversesections, x 10.Fig. 9. Willeyia bisidcata. Section through proboscis pore, x 45.Fig. 10. W. bistdcata. Schematic reconstruction as in fis;. 8. x 10.PLATE XLTI.Fig. 11. Spengelia porosa. Section through posterior part of proboscis, x 12.Fig. 12. Willeyia hisulcata. Section through anterior part of proboscis, x 30.Fig. 13. IF. bistdcata. Section through branchial region, x 22.Fig. 14. IF. bisidcata. Section through genital region, x 22.Fig. 15. IF. bisulcata. Section through hinder part of anterior neuropore. x 45.Fig. 16. IF bisulcata. Through anterior part of anterior neuropore, shewing the oesophageal nervecoming oflF on the left side of the figure, x 45.

THE ENTEEOPXEUSTA. 679Fig. 17. Ptychodera viridis. Section through post-branchial groove, x 12.Fig. 18. Pt. Jlava, var. jnuscula. Section just anterior to tlie proboscis pores, shewing tlie expansionof the nuchal skeleton over the racemose organ (r). x 45.Fig. 19. Pt. viridis. Section through anterior collar region, x 20.Fig. 20. Sp. maldivensis. Section through post-branchial groove, x 45.PLATE XLIII.All figures on this plate are from Pt. flava, var. parva.Fig. 21. Through anterior part of proboscis, x 30.Fig. 22. Through anterior portion of central proboscis complex, x 30.Fig. 23. Through specimen in which the two proboscis pores have a common opening near themid-dorsal line, x 54.Fig. 24. Through hinder part of proboscis shortly before the lateral diverticula of the stomochordappear, x 54.Fig. 25. Through region of the lateral divei-ticula of the stomochord. x 54.Fig. 26. Through tiie proboscis pores behind the lateral diverticula of the stomochord. x 54.Fig. 27. Through anterior cavit}' containing region of collar, x 30.Fig. 28. Through region of racemose organ, behind the proboscis pores, x 54.PLATE XLIV.Fig. 29. Pt. Jlava, var. asymmetrica. Section through collar cord, x 45.Fig. 30. Pt. Jlnva, var. parva. Section through same level as PI. XLIII. fig. 25, but throughanother specimen in which the lumen of the stomochord is obliterated instead of being patent.X 45.Fig. 31. Pt. Jlava, var. parva. Section through middle of collar region shewing longitudinal musclesarranged in bundles, x 20.Fig. 32. Pt. Jlava, var. parva. Section through proboscis pores. In this specimen the perihaemalspaces reach forwards to this level. More usually they commence shortly behind the pores(cf. PI. XLIII. figs. 23, 26). X 45.Fig. 33. Pt. Jlava, var. saxicola. Section just anterior to the proboscis pores shewing great widthof keel of nuchal skeleton, x 45.Fig. 34. Pt. Jlava, var. saxicola. Section through stomochord in region of lateral diverticula, x 85.Figs. 35, 36, 37. Pt. Jlava, var. saxicola. Sections through the pygochord. The three sections arefrom the same specimen ; fig. 35 is nearest to the anus, fig. 37 is furthest from it. x 85.Fig. 38. Pt. Jlava, var. saxicola. Through anterior branchial region, x 12.Fig. 39. Pt. Jlava, var. saxicola. Through posterior branchial region of same specimen as in fig. 38.X 12.Fig. 40. Pt. Jlava, var. saxicola. Through level immediately behind the post-branchial groove. Alsofrom same specimen as fig. 38. x 12.Fig. 41. Pt. Jlava, var. saxicola. Througli region of post-branchial groove. The genital pleuraeare still almost as large as in the branchial region, x 12.87—2

680 R. C. PUNNETT.PLATE XLV.Fig. 42. Pt. Jlava, var. gracilis. Section through hinder part of collar region, x 45.Fig. 43. Pt. Jlava, var. laccadivensis. Sections through stomochord. All x 85.a. Near anterior extremity.6. At anterior level of lateral diverticula.c. Through lateral diverticula at their maximum breadth.d. In region of nuchal skeleton.Fig. 44. Pt. Jlava, var. gracilis. Through stomochord, shewing completely obliterated lumen, x 85.Fig. 45. Pt. Jlava, var. cooperi. Through keel of nuchal skeleton, x 85.Fig. 46. Pt. Jlava, var. cooperi. Through proboscis stalk close to opening of proboscis pores, x 85.Fig. 47. Pt. Jlava, var. cooperi. Through post-branchial groove. The groove is large and thegenital pleurae well marked, x 45.PLATE XLVI.Sections through the region of the branchial and post-branchial groove in several species andvarieties of Ptychodera. All x 27.Fig. 48. Pt. Jlava, var. parva. Through middle of branchial region.Fig. 49. Pt. Jlava, var. laccadivensis. Through post-branchial groove.Fig. 50. Pt. Jlava, var. gracilis (Hulule). Through middle of branchial region.Fig. 51. Pt. jlava, var. laccadivensis. Through hind end of post-branchial groove.Fig. 52. Pt. asymmetrica. Through middle of branchial region.Fig. 53. Pt. Jlava, var. gracilis (Hulule). Through hind end of post-branchial groove.Fig. 54. Pt. Jlava, var. gracilis (Minikoi). Through branchial region.Fig. 55. Pt. Jlava, var. gracilis (Minikoi). Through hind end of post-branchial groove.Fig. 56. Pi. asymmetrica. Through posterior branchial region.Fig. 57. Pt. Jlava, var. laccadivensis. Through middle of branchial region.Fig. 58. Pt. asymmetrica. Through hind end of post-branchial groove.

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MARINECRUSTACEANS.PARTS X.AND XLBy L. a. Borradaile, M.A., Lecturer in Natural Sciences at SelivynCollege,Cambridge.(With Plates XLVII. and XLVIII. and Text-figures 122—6.)X. THE SPIDER-CRABS (OXYRHYNCHA).The Oxyrhyncha are a fairly well characterized group. Sharply separated, on the onehand from the Dromiacea by the coxal opening of the oviduct, the loss of the firstabdominal limb in the female, and the normal shape and position of the last pair of legs(except in two or three cases as Ocinopus (Fig. 123), Grypachaeus and Zehrida), and onthe other hand from the Oxystomata by the square mouth and the normal maxillipeds(PI. XLVII. fig. 5 h), they differ from the Brachyrhyncha in the shape of the body, whichis narrowed in the fore part, so that in most cases it is triangular, and has a well-markedrostrum (PL XLVII., and Text-figs. 122 and 123), and usually in the imperfection of the orbits.Slender legs and weak chelae are another common feature, but not a diagnostic one. Theirprevailing habitat may be summed up by saying that they are the crabs of the weed andweed-like animals, but this statement needs some explanation and qualification.The loss of their tail-fin has left the crabs, as a whole, a distinctly slower-movinggroup than most of the tailed Reptantia. To this there are, indeed, exceptions—as, forinstance, the Ocypodes on land and the swimming crabs in the water—but for the bulkof the Brachyura it holds good, and each of the sections of the tribe has had to meetthe difficulty in its own way. In the Brachyrhyncha the cuticle has generally becomethickened into a stout armour, while the crab keeps fairly active in its habits, at all eventsafter dusk, and usually defends itself vigorously with its strong chelae when it is attacked.In this legion protective coloration and shape are comparatively rare, and the habit ofcovering the body with foreign objects decidedly so (Caphyra), though the custom of hidingunder stones is common. The remaining groups have, so to say, accepted the situation.Driven by the loss of their tail-fin to lead a sluggish life, they have found safety inexaggerating this inertness and combining it with various devices for escaping observation.The Dromiacea hold foreign bodies over their backs with their hind legs, the Oxystomesbury themselves in sand or shingle, and in each of these groups the most characteristicfeatures, to which they owe their distinctness, are due to the method of concealments The'See above, p. 434.

(582 L. A. BORRADAILE.typical members of the Oxyrhyncha—the Maiidae'—have adopted another plan. They hidethemselves by covering their bodies with bits of seaweeds, zoophytes, or sponges, which areheld on by hooked or jagged hairs of special shape found on the body and limbs of thetrue spider-crabs and not elsewhere (PI. XLVII. figs. 3 c and 4 d). They are gathered andplaced in position by the crab itself, which uses for this purpose its chelipeds. These limbsare specially shaped so as to have a mobility not found in other crabs, and are thus ableto reach distant parts of the body and legs. In order that they may adhere better, thefragments of weed, etc. are treated with a secretion given out by glands on the firstmaxilliped"; and they not only remain in a living state, but often continue to grow, sothat in some genera it is not uncommon to find the whole crab as completely hidden bya single sponge as any Dromia. Besides seaweeds, the organisms used include sponges,hydroids, polyzoa, and ascidians, and in some cases barnacles and tubicolous worms addthemselves as self-invited guests. Several different kinds of organisms may sometimes befound on the back of one crab, but in most cases, very jjossibly in all, the species plantedby it are those amongst which it is living and are changed if it be placed in othersurroundings where they would be conspicuous. This implies considerable care in the choiceof the clothing, and indeed such may easily be seen to be bestowed if a captive individual,say a Maia squinado, be watched while it is disguising itself I have even seen this speciesQover its back with shingle when no weed was available. The number of hairs naturallyvaries, as does also the extent to which the crab is hidden, but it rarely happens (E'pialtus)that they are quite wanting.' Key to the fumiliei! of the Oxyrhyncha.I. Carapace thin and flat. First leg (cheliped) not long orspecially mobile or with fingers bent at an angle with thehand. Male opening sternal. [No orbits. Second jointof antennal stalk slender,fused with epistome but notwith front. No hooked hairs.] Hymenosomidae.II. Carapace not thin and flat (except Ocinopus). First legeither mobile or powerful with bent fingers.coxal.Male openingA. Chelipeds specially mobile, rarely much larger thanthe other legs or with fingers bent at an angle on thehand.Second joint of antenna well developed, generallyfused with epistome and often with front. Orbitsgenerally more or less incomplete. Hooked hairsalmost always present.Maiidae.B. Chelipeds not specially mobile, usua!l3' much longerand heavier than the other legs and with fingers benton the hand at an angle towards the side on whichthe fixed finger is set. Second joint of antenna small,short, and not fused with epistome or front.Orbitswell made. Hooked hairs almost always wanting.Parthenopidae.Key to the subfamilies of the Maiidae.I. Second joint of antenna very slender throughout its length.II.[No orbits. Eyestalks generally long.] Inachinae.Second joint of antenna not very slender.A. No true orbits (eyestalks hidden under a supraocularspine or sunken in the sides of a great rostrum).Second joint of antenna truncate-triangular. Eyestalksvery short. Acanthonychinae.B. True orbits, containing both supra- and postocularelements sheltering the eyes, are more or less completelyformed, except in a few genera where theeyestalks are long and slender. Second antenna-jointbroad, usually not truncate-triangular. Eyestalks longor short.1. A large, cupped, usually blunt postocular processpresent. Eyestalks short. Cornea of eyes not completelyhidden when they are folded back. Pisinae.2. Postocular process, if present, usually .sharp and notcupped, but if not so then cornea hidden (as alsoin most other cases). Eyestalks usually long.Maiinae.Key to the subfamilies of the Parthenopidae.I. Carapace usually triangular, sometimes suboval or subpentagonal.Bostrum simple. Chelipeds much biggerthan the other legs. Branchial regions of the bodydeeply separated from cardiac. Parthenopinae.II. Carapace usually sharply pentagonal. Rostrum cleftinto two. Chelipeds of moderate size. Branchialregions of the body not deeply separated from cardiac.Euniedoninae.- For an account of those structures in the Spider-Crabswhich are specially adapted to their habit of clothing themselves,see Aurivillius, Kong. Scenska Vet.-.ik. Hand. Bt.XXIII. no. 4 (1889).

MARINE CRUSTACEANS. 683Such habits as these need a corresponding habitat, and the Spider-Crabs are essentiallyhaunters of weeds, and weed-like animals. The larger kinds cling to the rocks and stoneson which grow the organisms they clothe themselves with. The walking-legs of such speciesusually end in strong, shai-p, curved claws by which they can hold fast to the ground.Smaller kinds often live on the weed itself, and these frequently bear hooked or evensub-chelate claws on the hinder legs with which to cling to the branches, while one orboth of the second and third pairs are long — probably because they are used in climbing(PI. XLVII. figs. 1, 3 and 4). The first pair (^chelipeds) are also sometimes used, monkeywise,in clambering. Research will no doubt show that some of the peculiar features ofparticular species and genera are adaptations to special kinds of sessile organisms. At presentI can only recall the flat, leaf-like body of Huenia, which resembles the Haliiueda-weedamong which it is generally found (see below, p. 686), and it is certainly the case thatvery many species show no preference whatever in this respect.The habit of living on or among sessile organisms is probably kept up by some ofthe members of the other two families of the Oxyrhyncha, although it is the Maiidaealone which clothe themselves in the way described above. Further information, however,is much needed on this point. The Hymenosomidae (Fig. 122) seem clearly adapted bytheir structure—their delicate bodies and slender legs with hooked end-joints—for living onplants or zoophytes. They may certainly sometimes be found in such situations, but arealso reported to have been taken under stones', a position for which their flat backs arenot unsuitable. Among the Parthenopidae, the Eumedoninae are probably guests of otherorganisms. Zehrida has, indeed, been taken among the spines of a sea-urchin whose colouringit assumes. But the Parthenopinae (PI. XLVII. fig. 5) have an entirely different habitat.The members of this subfamily have left the weed (that they originally had the samehabits as the Maiidae seems likely from the occurrence of hooked hairs, slight and few innumber, in certain members of the genus Lamhrus) and have taken up the same habitatas the Oxystomata—that is to say beds of sand and shingle. The result is a series ofmodifications strikingly like some of those which are found in the latter group-. Theoverlapping wings of the carapace which hide the legs of Calappa and Tlos reappear insuch forms as Cryptopodia, Heterocrypta and Oethra and less strongly marked in Larahrus,especially L. calappoides. The long chelipeds of some Leucosiids are repeated in an alteredshape in various species of Lamhrus and Parthenope. The bent fingers of Ranina and somespecies of Calappa are found throughout the group. In Lamhrus calappoides we find againthe flat hands of Calappa held against the breast. But the most striking of these likenessesis the arrangement of the inward channel for the breathing-stream in Aulacolamhrus, which,while it is wholly new, yet strongly recalls that of the Leucosiidae. In this subgenus, theunderside of the carapace (pterygostome) is traversed, on each side, just outside the thirdmaxilliped, by a deep groove which is covered in, not like the analogous channel in theLeucosiidae by the maxillipeds, but by thick fringes of hairs borne by the maxillipeds andby the carapace, becoming thus a closed tube leading from the front of the body to theopening of the gill-chamber at the base of the chelipeds (PI. XLVII. fig. 6). A similar1 Adams and White, Crustacea of the Samarang. The ganisms. Or, again, it may be that the hollows under theanthors make the same statement about Trapezia, which is stones from which the Elamena was taken were lined ascertainly a coral crab. Perhaps these genera take shelter such hollows often are, with a scrubby growth of weed.under stones when they are by some accident removed from - See above, pp. i'6i, 435.the neighbourhood of their natural habitat, growing or-

684 L. A. BORRADAILE.arrangement is found in the other subgenera of Lambrus^. In this case, however, thereare two shallow grooves, an outer one running outward and an inner one running forwardfrom the gill-opening, and both uncovered (PI. XLVII. fig. 5 b). The rough, knobbed backof the Parthenopinae is like that of Calappn, but a similar texture is so common amongcrabs that little can be argued from it. Probably it is less conspicuous on a sandy bottomwith coral pebbles than a quite smooth object would be.We have already stated that the Oxyrhyncha are among the sluggish groups of crabs.When they are seized they do not attempt to defend themselves with their chelae, butmove their legs feebly and aimlessly. Indeed the Parthenopinae—like the Calappidae inthis respect also—often seem to be hypnotised by being moved, drawing up their legs underthem and remaining still. In general the intelligence of the group is of a low order, withthe single exception of their cleverness in disguise, which, after all, is probably no morethan a fairlysimple reflex.Fig. 1'22. Elamena gracilis; a. whole auimal, h. outside of hand.Of the 29 species in the collection made by the expedition, three are new. The restare all recorded from the Indian region by Major Alcock^ with the exception of two whichwere described as new by Miss Rathbun in her account of Prof. Agassiz's Maldive Crabs ^The following systematic list sets forth these species in order.Family Hymenosomidae.Genus Elamena H. M.-Edw., 1837.1. Elamena gracilis, n. sp. (Fig. 122)Diagnosis :" An Elamena in which the sides of the hinder part of the body are straightfrom the 4th to the 1st pair of legs, and then turn inwards almost at right angles to' Owing to lack of material I am unable to say whether Journ. As. Soc. Bengal.this groove is found throughout Parthenopinae. ^ Bull. ilus. Harvard, xxxix. 5 (1902).- In his series of papers on the Indian Ciabs in the

in;MARINE CRUSTACEANS. 685join the fore part, which is triangular, with very slightly irregular sides; the front alsotriangular but with indications of two teeth at its sides; the eyes showing a small partof the cornea at the sides of the front when seen from above ; the chelipeds short, slender,with narrow, sjDooned fingers about as long as the palms ; and the walking-legs slender,with a spine at the end of the merojDodite, and the last joint strongly hooked, with agroup of little thorns underneath at the tij) and a fringe of hair all along."Length of longest specimen : 6 mm. Breadth : 7 mm. Colour : spirit, pale yellowwhen alive, legs black-brown, rest of body transparent.A female was taken at Minikoi, and a male and female at Hulule, Male Atoll, all onthe reefFamily Maiidae.Subfamily Inachinae. Genus Achaeus Leach, 1815.2. lAchaeus spinosus Miers, 1879. Alcock, i. p. 171'.My specimen agrees with Alcock's and Miers' descriptions, but the last two pairs oflegs have strongly curved end-joints. Miers and Alcock only mention the last pair.Dredged in Mahlos Atoll in 24 fathoms.Fig. 123. Ocinopus aranea ; a. whole animal, b. two of the hairs on the hinder pair of legs, c. one of the long hairson the legs of the second and third pairs, d. hooked hairs.Genus Ocinopus de Haan, 1837.3. Ocinopus aranea de Haan, 1837. Alcock, i. p. 183 (Fig. 123).The shape of the lobes at the tip of the rostrum in this species varies somewhat.A very common crab, taken practically throughout the group in 19—45 fathoms.' For a statement of the principles on which references Alcock's paper on the Indian Oxyrhyncha appeared in Journ.are given in this series of papers see above, p. 192. Major As. Soc. Bengal, lxiv. ii. 2, p. 157 (1895).G. II. 88

:686 L. A. BORRADAILE.Subfamily Acanthonychinae. Genus Xeriocarcinus White, 1847.4. Xetwcarcinus tuberculatus White, 1847. Alcock, i. p. 192.Dredged outside Fadifolu Atoll, in 70 fathoms.Genus Menaethius H. M.-Edw., 1834.5. Menaethius monoceros (Latr.), 1825. Alcock, i. p. 197.A common species, taken in Male, Fadifolu, Minikoi, and Goifurfehendu Atolls down to6 fathoms.Genus Huenia de Haan, 1837.6. Huenia proteus de Haan, 1837. Alcock, i. p. 195 (PI. XLVII. figs. 1, 2).In the extraordinarily variable shape of its body, this crab is fully worthy of its name.The simplest form is found in most of the males, which are flat and triangular, much likeMenaethius, with a long, sharp rostrum (PI. XLVII. fig. 1).What may be the habitat of these males is yet to be settledthe specimen figured carried a large flat piece of a green weed,held on its rostrum by means of the hooked hairs always foundthere in this species. On the other hand, most of the femalesand some of the males—true males, not "unsexed females" withparasites — have the body widened into a leaf-like shape byoutgrowths of the hepatic and bi'anchial regions (PI. XLVII.fig. 2). These individuals, at least in most cases, live on theflat Halimeda-weed, which they closely resemble both in shapeand colour. Figure 124 is given to show this likeness. Some ofthe females, however, come near the three-cornered shape of theordinary male. This, and the fact that intermediates are foundin both sexes, prevents us from calling the phenomenon" dimorphism." Another interesting feature is shown by thewalking legs. The last joint in these limbs is strongly toothed,and can be shut back at a sharp angle on the one before it.In the broad individuals the legs are short and stout andkeeled to look like the edges of Balimeda " leaves," and herethe whole under-edge of the last joint but one is hairy; butin the triangular form, where the legs are long and slender,there is a special tuft of hairs to meet the end-joint, and thistuft is often raised on a knob. The whole structure thus formed is all but subchelate andseems clearly adapted for holding on by.Fig. 124.A sprig of Halimeda-v/eeiwith a specimen of Huenia proteus,showing the likeness of the latterto a " leaf" of the weed.The surface of the body of these crabs may be seen under a high magnification tohave the curious graving shown in fig. 1 a, on Plate XLVII.The species was taken in Male Atoll on the reef, and dredged fi-om 22 fathoms inKolumadulu Atoll.

MARINE CRaSTACEANS. 687Subfamily Pisinae. Genus Naxioides A. M.-Edw., 1865.The synonymy of this genus is discussed by Rathbun, P7-oc. Biol. Soc. Washington, XI.p. 157 (1897).7. Naxioides hirta A. M.-Edw., 1865.Naocia hirta, Alcock, loc. cit. p. 218.Taken in Kolumadulu, Suvadiva, Haddumati, and South Nilandu Atolls in 30—40 fathoms.8. Naxioides sjnnigera, n. sp. (PI. XLVII. fig. 3).Diagnosis: "A Naonoides with the horns more than half the length of the body, bearingthe accessor}' thorn a third of their length from the end ; the body hairy, with many knobsand thorns, of which the largest are three in a row on the gastric region, two on thecardiac, one on the intestinal, three in a triangle on the branchial, with one in front ofthem, and one on each eye-hood, these latter being quite upright, but bent slightly forwardsat the tip, no thorn at the angle of the mouth, two knobs on the pterygostome, twothorns on the outside of the basal joint of the antenna; the chelipeds slender, little longerthan the body, the fingers half the length of the palm, finely toothed and meeting alongnearly their whole length, a spine at the end of the arm ; and the walking legs slender,the first pair very long, a long sjiine at the end of the meropodite of this limb, a shortone on the next, and none on the hinder two."Length: 11 mm. Breadth: 8 mm. Colour in spirit: white.Allied to N'. cerastes (Ortm.), 1894.Three males dredged in 30 fathoms in North Male Atoll.Genus Halimus Latr., 1829.For the synonymy of this genus, which is identical with Hyastenus White, 1847, andnot Naxia Leach, 1828, see Rathbun, Proc. Biol. Soc. Washington, xi. p. 157 (1897).9. Halimus tenuicornis (Pocock), 1890. Alcock, i. p. 215.The colour of this species as preserved in formalin is white with bright pink markings.It was dredged in South Nilandu, Male, Mulaku, Felidu and North Male Atolls in 25—30fathoms.10. Halimus gracilirostris (Miers), 1879. Alcock, i. p. 215.Dredged throughout the gi-oup in 20—70 fathoms.11. Halimus diacanthus (de Haan), 1837. Alcock, I. p. 210.Found on a black crinoid dredged in 30 fathoms in South Nilandu Atoll.12. Halimus calvarius (Ale), 1895. Alcock, i. p. 213.Dredged in South Nilandu, Mulaku, Suvadiva, Haddumati, and North Male Atolls in19_40 fathoms.13. Halimus convexus (Miers), 1884. Alcock, i. p. 216.The one specimen in the collection is a female, and differs from Miers' (a male) in that:(i) the horns are less strongly divergent, (ii) the palm is slenderer and the fingers much less88—2

688 L- A. BORRADAILE.gaping. The species is allied to H. calvarius but differs in that: (i) the horns are moreslender and diverge more strongly, curving, as well as slanting, outwards, (ii) there is notrace of a knob on the gastric mound, which is also more prominent, (iii) there is noepibranchial spinule or intestinal spine, (iv) the carapace is narrower, and (v) the palm israther more swollen. It was dredged in 30 fathoms in Suvadiva Atoll.14. Halimus espinosus, n. sp. (PL XLVII. fig. 4).The group of forms akin to H. diacanthus (including var. elongata Ortm., 1893, H.suhinermis Zehnter, 1894, H. convexus Miers, 1884, and H. calvarius Ale, 1895) are in alllikelihood no more than varieties of one variable species. The collection contains a specimenof another such form, which I describe here. The following characters, taken together, separateit from its allies mentioned above: (i) carapace narrow (10:6); (ii) gastric region swollen,with traces of the knob; (iii) horns rather less than half the length of the carapace, straight,not very divergent ;(iv) a spinule on each branchial region and a low knob in place of theintestinal spine; (v) the outer angle of the basal antennal joint not strongly marked. Thespecimens, which are both males, were dredged in Haddumati Atoll in 35 and 39 fathoms.15. Halimus agassizi Rathb., 1902.Halimus agassizii, Rathbun, Bull. Mus. Har-vard, XXXix. 5, p. 133, fig. 6.The females of this species have very slender chelipeds with long narrow palms andshort fingers, which gape very slightly. Miss Rathbun's only specimen was taken in thesame locality as ours, Nilandu Atoll, and in practically the same depth, 24 fathoms.Genus Phalangipus Latr., 1825.Miss Rathbun (Proc. Biol. Soc. Washington, XI. p. 159, 1897) has shown that this namemust be substituted for Egeria Leach, 1815, which is preoccupied.16. Phalangipus arachnoides Latr., 1825. Alcock, I. p. 223.Dredged in Mulaku, South Nilandu, and Felidu Atolls, in 25—36 fathoms.Genus Tylocarcinus Miers, 1879.17. Tylocarcinus styx (Hbst.), 1803. Alcock, i. p. 235.Taken on the reef in Male, Fadifolu, and Goifurfehendu Atolls.Subfamily IVIaiinae. Genus Schizophrys White, 1848.18. Schizophrys aspera (A. M.-Edw.), 1834. Alcock, i. p. 243.Taken on the reef in Male and Fadifolu Atolls, and dredged in 34 fathoms in Feliduand 20 fathoms in Suvadiva Atoll.Genus Gyclax Dana, 1852.19. Cyclax (Cyclomaia) suhorhicularis (Stimps.), 1857. Alcock, i. p. 245.Taken on the reef at Hulule, Male Atoll.

MARINE CRUSTACEANS. 689Genus Micippa Leach, 1816.20. Alicippa philyra (Hbst.), 1803. Alcock, I. p. 249.Taken on the reef at Hulule, Male Atoll, and dredged in Kolumadulu, South Nilandu,Fadifolu, Suvadiva and North Male Atolls in 20—35 fathoms.21. Micippa margaritifera (Hend.), 1893. Alcock, i. jx 253.Dredged in Suvadiva Atoll in 43 fathoms.22. Micippa parca Ale, 1895. Alcock, i. p. 253.I think that this form should have specific rank, rather than that of a variety ofM. margaritifera, given to it by Alcock.Dredged in 20 and 25 fathoms in Mahlos and South Nilandu Atolls respectively.Genus Macrocoeloma Miers, 1879.23. Macrocoeloma mimmifer Ale, 1895. Alcock, I. p. 255.Almost all the spines on my specimens end in a round knob. Alcock does not mentionthis, but such knobs were present on several of the spines in the individual he figures.In my specimen thickenings of a like kind are set on the tips of the front. Alcock'sfigure, however, shows none. The knobs cannot be rubbed off and do not seem to be dueto foreign growths of any kind.The species was dredged in 30 fathoms in South Nilandu, and in 23 fathoms inMahlos Atoll.Family Parthenopidae.Subfamily Parthenopinae. Genus Lambriis Leach, 1815.24. Lamhrus {Rhinolamhrus) bispinosus Rathb., 1902.Lambrus (Rhinolambrus) bispinosus, Rathbun, Bull. Mus. Harvard, xxxix. 5, p. 134,figs. 1, 2.In her description of this species, Miss Rathbun says that the upper side of the handbears two lobes. Later she says that the species is separated fi'om L. confragosus (amongother differences) by the presence of only one lobe in this position. Her figure and myspecimens bear out the latter statement.Dredged in South Nilandu Atoll in 25 fathoms.25. Lavibrus {Rhinolambrus) pelagicus Rupp., 1830. Alcock, I. p. 267.The granules on the back are quite well marked in my specimens, as in Milne-Edwards'figure {Nouv. Arch. Mus. VIII. PI. XIV. fig. 4). It would seem that Alcock had found inthe Andamans local races both of this species and of L. gracilis, in which the granuleswere reduced in size and distinctness.Dredged in Mulaku, Suvadiva, and Addu Atolls, in 28—43 fathoms.

:690 L. A. BORRADAILE.26. Lambrus (Rhinolambrus) gracilis Dana, 1852. Alcock, I. p. 269.The specimens which I assign to this species agree with Alcock's description fully,except that the surface of the carapace is not absolutely smooth, there being several granulesround the cardiac spine and along the branchial ridges.Dredged in Felidu, Fadifolu and Suvadiva Atolls, in 22—43 fathoms.27. Lambrus (Rhinolambrus) turriger Ad. and Wh., 1847. Alcock, i. p. 269 (PI. XLVII.fig. 5).Dredged in South Nilandu, Felidu, Mulaku, Haddumati, Suvadiva, Kolumadulu andNorth Male Atolls, in 2.5—42 fathoms.28. Lambrus (Aulacolambrus) sculptus A. M.-Edw., 1872. Alcock, i. p. 272 (PI. XLVII.fig. 6).Dredged in South Nilandu, Felidu, Mulaku, and Suvadiva Atolls, in 20—43 fathoms.29. Lambrus (Parthenolavibrus) calappoides Ad. and Wh., 1847. Alcock, i. p. 275.Dredged in South Nilandu and Suvadiva in 36 and 35 fathoms respectively.XI.ON THE CLASSIFICATION AND GENEALOGY OF THEREPTANT DECAPODS.Besides the brachyurous Crabs, Boas' Reptantia' comprised sundry groups which are notbrachyurous, that is have a pair of biramous limbs on the sixth segment of the abdomen,which bears traces of adaptation to other purposes than reproduction, such as swimmingor holding on a shell, and have also no fusion between the rostrum or front and theepistome and no angle on the endopodite of the first maxilliped. The following are thenames of these groups : Eryonidea, Scyllaridea (= Loricata), Nephropsidea (= Homaridea andAstacidea), Thalassinidea, Paguridea, Galatheidea, and Hippidea, the last three being togetherknown as Anomala by Boas and most other writers.Our present object is to arrange these divisions according to their relationships, and todo this we must first of all form an idea of the ancestor from which they may be supposedto be descended. More space would be needed than can be spared here to set forth indetail the process of comparison of the various types with one another and with the prawnsof the Stenopidea and Penaeidea, by which this result may be reached, and indeed thismight after all be hardly worth while, for the following statement will, I think, commenditself to those who have studied the subject as on the whole probable.The forebears of the reptant Decapods, if they could be examined, would probably showthe following characters(1) The rostrum of a good size, flat but keeled, and narrowly triangular.(2) The carapace subcylindrical, free from the epistome both at the sides and in the middle,overlapped behind by a process of the first abdominal segment on each side, and marked by thefollowing grooves : on the back two running transversely (the first, line e of Boas, is Bouvier's' See above, Art. iv. vol. i. p. 424.

—MARINE CRUSTACEANS. 691cervical groove, and the second, line c of Boas, is Bouvier's branchial groove, ordinarily known asthe cervical groove; it would be well if these were known as the first and second cervical grooves);at tlie sides tliree transverse grooves slanting forwards, the first two being prolongations of thetwo cervical grooves and the third being line a of Boas ;and two irregular longitudinal grooves, theupper, line d of Boas, connecting the first cervical groove with the fore edge below the antenna,and the second, line h, 6' of Boas, starting from the lower end of a and joining tlie lower endsof the two cervical grooves with the fore edge some way below the line

692 L. A. BORRADAILE.(12) The third maxilliped with the exopodite shorter tlian the endopodite, carrying a straight,jointed flagellum directed forwards, and the endopodite narrow, with separate ischiopodite andmeropodite.(13) All the legs seven-jointed. The first three pairs chelate with normal chelae, the firstthe greatest, equal, the fourth pair simple, the fifth pair simple (?) and having its last two jointsslightly twisted so that, when the basal joints are pressed against the sides of the body, whilethe last joint of the fourth pair points downwards and backwards, that of the fifth pair pointsforwards and inwards'.(14) The gi//s many, including mastigobranchs and podobranchs on all the thoracic limbs butthe last, arthrobranchs on all but the first and last, and pleurobranchs on the last four.(15) The thoracic segments which bear the legs with distinct sterna, which are not very broad,but grow broader from before backwards, and are all fused except the last^.(16) The first pair of abdominal limbs unbranched. Those of the second to fifth segmentswith two fairly broad branches, the inner of which bears an appetidix interna (Fig. 126 c). The lastpair about as long as the telson, with broadly oval branches, across the outer of which is a suture.The internal anatomy of the various groups is not yet well enough known to allow of generalstatements being made about it.The animal was hatched in the Zoea stage, with a segmented abdomen but no limbs behindthe third maxilliped, and passed through a Mysis stage with exopodites on all the legs.The descendants of the crustacean which we have thus reconstructed fall into twosets, one comprising the Eryonidea, Scyllaridea, and Nephiopsidea, in which the abdomenis strong and well-armoured, stretched out unprotected, and used as a swimming organ bymeans of its tail-fin, and the other containing the rest of the groups, in which it has forsome reason become a burden and a source of danger to be protected and kept fromexposure, even though it be still shaped and used for swimming. The fii-st of these setsis on a lower and more primitive grade of organisation than the second. This is shown(1) by the abdomen, with its stout armour, overlapping terga and pleura, strong processesto clip the carapace on the first segment, broad tail-fin, and, in the Eryonidea and Scyllaridea,appendices internae. To this form of abdomen, which is always carried at length, I shallrestrict the term " macrurous." (2) by the legs, which in the Eryonidea and Nephropsideaare chelate in the first three pairs and have seven joints (except for the first pair of theNephropsidea) whereas in all other Reptantia they have only six, owing to the fusion ofthe basipodite and ischiopodite, (3) by the large number of the gills, (4) by the slenderthird maxillipeds with their long flagella directed forwards, (5) by the broad antennal scale ofthe Eryonidea and Nephropsidea. Of course some of the foregoing chai-acters are found inprimitive members of other groups, but they stamp this set of groups as a whole. Of thethree macrurous groups, the Eryonidea and Scyllaridea are more nearly allied together thaneither of them is to the Nephropsidea. They have both lost, or much reduced, their rostrum(except Palinurellus), reduced the inner lobes of the second maxilla, and fused their carapaceat the sides with the epistome, but they have kept the appendices internae. Their body' This character, though it is most prominent in the but also in the Thalassinidea, Potamobiidae and ParastacidaeAnomala and Thalassinidea and the losver Crabs, is seen to and in the prawn Stenopus. In Penaeus the anterior sternasome extent even in the more primitive groups, as the are free, but the last two are joined by secondary thickeningsPalinuridae and Potamobiidae.- A primitive feature, found not only in Boas' Anomalain the membrane between them.

MARINE CRUSTACEANS. 693shows a tendency to be flattened. The Ncphropsidea differ from them in all these respects.Between the Eryonidea and the Scyllaridea the most striking difference lies in the factthat in the former all the legs are chelate and in the latter none are so. The Eryonideaare the more primitive in keeping the antennal scale, the joint between the ischiopoditeand meropodite, and the chelae on the first three legs.aFig. 126. Limbs of A.rhis acanthus; a. second maxilla, b. first maxilliped, c. abdominal limb of the third pair.1. gnathobase or first lobe of coxopodite, 2. endopodite, B. appendix interna, 4. lobes of basipodite.In considering the second set of groups, we have first to settle whether to look upon themas of common descent and treat them as a whole, or whether we must find a separate pointof origin for each of them from among the Macrura. Now it may be allowed at the outsetthat there is but one character that every member of them shares with the rest. In themacrurous groups the first three pairs of legs are all alike, adapted either to seizing or tocrawling— chelate, that is, or simple. But in the modified groups we are now dealing withthe third pair is never adapted to the same end as the first. In the overwhelming majoritythe first pair are chelate or subchelate' and the third used for walking, and in the Hippidae,where the first are simple and straight, the third are hooked and flattened for burrowing orswimming. Nor i-s this point an unimportant one, for the likeness of the first three legsis a heritage from the penaeid prawns, and as such is of considerable value. Moreover itis possible to find a number of characters which, while they are not seen in every memberof the non-macrurous groups, are yet common in each of them, and do not occur elsewhere.These are: (1) a large gnathobase, or inner coxopoditic lobe, on the second maxilla (Fig. 126a),(2) the shape of the first maxilliped, which has a broad but shallow basipoditic lobe, whoseinner margin is in the same line with that of the coxopodite^ and a broad basal half tothe exopodite (Fig. 126 b), (3) the flagella of the maxillipeds turned inwards and curvedforwards at their ends, (4) reduction in various ways of the abdomen, (.5) the presence ofbackward prolongations of the longitudinal lines of the carapacel Since, however, numbers(3) to (5) are less strongly marked in the more primitive forms of some of the groujjs, itis doubtful whether much stress can be laid upon them.Taking it for granted, then, that the non-macrurous Decapods had a common, if remote,ancestor, it remains to be seen where that ancestor must be placed with regard to the1 Gebicula seems at first sight to be an exception to this,but there is on the propodite a strong tooth near the endwhich seems almost certain tu be used in the same way as theG. II." thumb" of the allied Upogebia.- Found also in at least one species of Nephropsis.' See above, footnote to p. 691.89

694 L. A. BORRADAILE.macrurous groups. For this purpose we must add to the list above certain other characterswhich, either from their own primitive character or because they are found in many of theprimitive members of the groups we are trying to place, may be attributed to the forebearsof these groups : (6) a large gill-formula, including all the gills of the ancestral reptant',(7) a small thorn-like antennal scale", (8) the last pair of legs not only on a free sternum'as in the Potamobiidae and Parastacidae, and slightly twisted at the end as in mostmacrurous Reptantia, but distinctly smaller than the fourth pair, removed from them, andcarried more dorsally, (9) a rather short and broad rostrum, (10) appendices internae onabdominal limbs', (11) a transverse suture on the telson-*.Numbers (6) to (9) of these remove the crustaceans in which they are found from theneighbourhood of the Eryonidea and Scyllaridea, since they are primitive features that thelatter have lost. Numbers (6) and (10) remove them for the same reason from theNephropsidea, to which, nevertheless, they are more akin than to the other macrurous groups.The jaws and the last thoracic sternum, but not the structure of the gills or the grooveson the carapace, are more like those of the Potamobiidae than those of the Nephropsidae.Assuming, as above, a common descent for the Crabs, Anomala and Thalassinidea, wemust at the same time admit that they very early divided into two widely separatedbranches, one containing the Crabs and the other the remaining groups. The characters bywhich this separation is shown are the following: (1) The great reduction of the abdomenin the Crabs. This is entirely independent of similar developments in the higher Anomala,for the more primitive of the Paguridea and Thalassinidea, though they share the tendency,common to the whole assemblage of families under discussion, to shelter and protect theirabdomen, have as yet been hardly more affected by it than, say, the burrowing genera ofNephropsidea, which are quite macrurous, while the primitive Galatheidea are little betterin this respect. Moreover, in the Crabs, the reduction has gone so far that the abdomen,having lost its sixth pair of limbs (except for doubtful, unbranched vestiges in some Dromiidea),is now fitted for, and shows traces of. no other function than those connected with reproduction,while in the Anomala and Thalassinidea, though some of its macrurous features arealways reduced, it has kept the sixth pair of limbs and nearly always uses them either forswimming or for holding on a shell. The Lithodinea alone form an exception to this statement,but in them the asymmetry of the abdomen clearly recalls its former use, as in theHermit crabs, to hold on a shell. These two types of abdomen—of which one does, whilethe other does not, show traces of adaptation to some other function than that of reproduction—I propose to call the " brachyurous" and "anomurous" respectively. (2) The carapace, whichin the Anomala and Thalassinidea remains free, is in the Crabs fused with the epistome bothat the sides and (except in Homolodromia) in the middle, under the front. (3) The antennalscale, which in many Anomala and Thalassinidea remains and is moveable, is never found inthat condition in the Crabs. (4) The endopodite of the first maxilliped is broad and hasnearly always an outer angle in the Crabs (see above, p. 425, fig. 110), but has not this shapein the Anomala and Thalassinidea, though some Hippidea approach it. (5) There are neverappendices internae on the abdominal limbs of the Crabs, whereas these structures are presentin most Thalassinidea and some Anomala. (6) The third pair of maxillipeds of the Crabs are' See above, p. 692. This is shown by Jaxea, Homolo- is fused to the stalk.dromia, etc. 3 jjot found in the Crabs.^ Among the Crabs found only in Homolodromia, where it*Found in certain Galatheidea and Paguridea.

MARINE CRUSTACEANS. 695usually broad, forming a cover to the mouth, whereas those of the Thalassinidea and Anomalaare only exceptionally so. These characters, however, are in themselves hardly enough tonegative the supposition that the Crabs have originated from one of the other non-macrurousgroups. What does make it impossible to derive them fi"om the Anomala is the presencein the primitive crab Homolodromia of podobranchs on some of the legs, while an originfrom the Thalassinidea is equally untenable on account of the less primitive condition of thegrooves of the carapace and the reduction of the endopodite and flagellum of the firstmaxilliped in the latter group.We are now left with the Thalassinidea and the three divisions of the Anomala stillunaccounted for. Among these there can be no question that the Thalassinidea are, as awhole, the most primitive. Their straight symmetrical abdomen, with well-developed biramouslimbs on all the segments except the first, and the sixth pair broad and flat in all butThalassina, the presence in most of appendices internae, and in some of good pleura, thesimple legs of the fourth pair and sometimes also of the fifth, the rostrum usually welldeveloped,the moveable antennal scale seldom wholly lost, and the large gill-formulae ofmany genera, extending from the second maxilliped to the fourth leg, with mastigobranchs,podobranchs, arthrobranchs and sometimes pleurobranchs—all these point to the same conclusion.Nor can there be any doubt that the Paguridea and the Thalassinidea are closelyakin and have branched off from the same not very remote ancestor. The only differencesbetween the Axiidae and the primitive Pagurids with symmetrical abdomen such as Pylochelesare the presence of a pleurobranch on the last leg, a suture across the telson in some species(which is never found in Thalassinidea), better developed eyes', the loss of epipodites on thelegs, a reduced rostrum, subchelate legs of the fourth pair, and the branches of the last pairof abdominal limbs narrow and not adapted for swimming. The first three of these features,being primitive, show that the Paguridea are not to be derived from any of the existingThalassinidea and the remainder make it equally impossible to derive the latter group fromthe former. The two meet at a point below otir present horizon.The Galatheidea join the stem from which the last two groups arise before itsbifurcation, that is,- they are less closely akin to either of these than the latter are to oneanother. The fact that they may have epipodites on some of the legs, and the more primitiveshape of the rostrum and sixth pair of abdominal appendages make it impossible to placetheir ancestor within the present limits of the Paguridea. The suture on the telson andthe pleurobranch on the last leg remove it also from the Thalassinidea. And the generalshape of the body, depressed, with broad flat abdomen carrying long pleura and bent underthe thorax, is so different from the compressed body, with straight abdomen, of the primitivePaguridea and Thalassinidea that there can be little doubt that the ancestral Galatheid leftthe non-macrurous stock, after the Crabs indeed, but before it gave rise to the Thalassinidsor Hermit-crabs. As for the linea anomurica, this is found not only in the Galatheidea andPaguridea but also very distinctly in Callianassa novaebritanniae, and it is curious to noticethat it is wanting in the primitive Pagurids such as Pylocheles, and most Thalassinids as inAarius, and that in the Galatheid Aeglea, which is also primitive in many respects, the hinderpart is again wanting. Thus it would seem as though this line appeared only in the higherand more typical forms of each group. The Hippidea present a very difficult problem. On1 Such species as Axiopsis clypeatus, however, have the eyes well developed, though not so large as those of thePaguridea.89—2

:696 L. A. BORRADAILE.the whole, however, their general shape of body, with a bent abdomen carrying good pleura,subcylindrical or depressed cephalothorax, and fourth pair of legs like the third rather thanthe fifth, shows a nearer kinship to the Galatheidea than to any of the other groups, andin the absence of any evidence to the contrary this judgment must stand. As for theirlikeness to the Raninidae among the Crabs, an admission that this indicated relationship wouldlead to great difficulties, as for instance that the Raninidae must either be removed fromthe closely related Oxystomes or the latter be supposed to be derived by modification fromthe highly specialised Hippidea—in itself a very unlikely speculation.Each of the above groups has its peculiar habits and habitat. The Galatheidea hideunder stones or dwell in weed. The Thalassinidea generally make burrows, but the moreprimitive genera among them show a tendency to shelter in weed or sponges. The Paguridea(except Lithodinea) place their abdomen in the hollow of some foreign body, which is usuallya gastropod shell, but in the primitive genera may be a stone or a sponge. The Hippideabury themselves in the sand. Of these habits, that of the Galatheidea is the least specialisedand could easily have given rise to the others.We are now in a position to sum up in the form of a tree the results reached in thisand former articles (PI. XLVIII.). When this is done two facts of importance appear. Firstthat the proper place of the Thalassinidea is in the midst of the anomurous groups, andthat they must no longer be classed with the Macrura, and secondly that, when this changeis made, the Anomura, like the Brachyura, become a true, monophyletic group. Thus thereptant decapods fall into three divisions, Brachyura, Anomura' and Macrura. To the subjectof the taxonomic value of these groups and their relation to the natant families I hope toreturn later on. For the present they may be called suborders'-.The following keys give more precisely the classification of the groups discussed aboveKey to the reptant suborders of the Decapoda.I. 3rd pair of legs like the first, either chelate or simple and subcylindrical. Abdomen macrurous(straight, symmetrical, well armoured, with good pleura and strong, broad tail-fin, a lobe onthe first segment clipping the carapace). Gnathobase of 2nd maxilla narrow. Basipoditic lobeof 1st maxilliped usually deep. Exopodites of maxillipeds witli lash directed forwards. Gillsnumerous. [Last thoracic segment with legs not difl'ering greatly from the rest and sternumrarely free.] Macrura.II. 3rd pair of legs unlike the tirst^ never chelate. Abdomen rarely macrurous. Gnathobase of2nd maxilla typically broad. Basipoditic lobe of 1st maxilliped broad but shallow, its inneredge in a line with that of tlie coxopodite. Exopodites of maxillipeds with lash, when present,nearly always bent inwards. Gills usually few. Last thoracic segment with limbs often differinggreatly from the rest and sternum free or not.]. Carapace not fused with epistome. Last thoracic sternum free, its legs diflfering always clearlyin size and position and nearly always in shape from the third pair. Abdomen anomurous(reduced in some of its features but showing clear traces of some other function than thatof reproduction and almost always carrying biramous limbs on the 6th segment) or, rarely,1Unlike Boas' term " Anomala," the name " Anomura" which it has not had before,'^has had very different meanings in the pages of different The Brachyura is ranked lower on p. 427.writers. This fact allows it to be used here with a denotation ' See footnote to p. 693.

MARINE CRUSTACEANS. 697macrurous. A moveable autennal scale often present. Third pair of maxillipeds usuallynarrow. Anomura.2. Carapace fused with epistome at the sides and nearly always in the middle. Last thoracicsternum fused with the rest, its legs often like the others. Abdomen brachyurous (small,straight, symmetrical, bent under the thorax, showing no traces of any other function thanthat of reproduction, and without biramous limbs on the 6th segment). Never a moveableantennal scale. 3rd pair of maxillipeds usually narrow. Brachyura'.Key to the tribes of the reptant Macrura.I. Carapace fused at the sides to the epistome. Rostrum small or wanting (except Palinurellus).Inner lobes of 2nd maxillae and 1st maxillipeds reduced. An appendix interna on some ofthe abdominal limbs, at least in the female, but the exopodite of the last pair without sharpsuture. Body often depressed.1. Carapace gripped by first abdominal segment alone. First joint of antenna not fused withepistome ; a scale present on this limb. All the legs, except sometimes the last pair, chelate;the first longer than the rest. Unbranched limbs on the first abdominal segment. Tail-finnot softer behind than before, without sutures. Telson pointed. Eryonidea.2. Carapace gripped between a lobe on the 1st abdominal segment and a knob on the sideof the last thoracic segment. First joint of antenna fused with epistome ; no scale on thislimb. None of the legs much longer than the rest or, except sometimes the first pair,chelate. No limbs on the 1st abdominal segment. Tail-fin divided by indistinct suturesinto a soft hinder half and a harder front half. Telson roughly squared behind. Scyllaridea^.II. Carapace free from the epistome. Rostrum of good size. Inner lobes of 2nd maxillae and1st maxillipeds not reduced. No appendix interna, but the exopodite of the last abdominallimb divided by a suture. Body subcylindrical. [Carapace gripped by first abdominal segmentonly. 1st joint of antenna free. A scale present. First three legs chelate, first pair thelongest. Telson firm, squared, often sutured.] Nepliropsidea.Key to the tribes of the Anomura.I. End-joints in 2nd to 4th legs curved and flattened. First pair styliform or subchelate. [Tail-finnot adapted for swimming. Abdomen bent under thorax. Rostrum small or wanting. 3rd pairof maxillipeds carry no mastigobranchs.] Uippidea'.II. End-joints in 2nd to 4th legs not curved and flattened. First pair not styliform, rarelysubchelate.1. Cth abdominal limb adapted for swimming (except in Thalassina where it is styliform.Pleura usually well developed. Abdomen symmetrical.a. Body depressed. A pleurobranch to the last leg. Often a transverse suture on thetelson. Abdomen more or less bent under the thorax. Galatheidea.b. Body compressed. No pleurobranch to the last leg. No transverse suture on the telson.Abdomen straight. Thalassinidea^.' For a classification of the Crabs, with keys, see above, articles which deal with them.vol. I. pp. 426 ff. ^ For a classification of this group, with keys, see Ann.- Keys to the families of these groups will be given iu the Mag. N. H. (7), xii.

698 L. A. BORRADAILE.2. 6th alxloniinal limb, when present, has the branches neither broad nor styliform but adaptedfor holding the body into hollow objects. Pleura very rare. Abdomen nearly alwaysasymmetrical and either soft and twisted, or bent under the thorax. Paguridea.Key to tlie subtribes of the Paguridea.I. Abdomen stiaight or twisted. Carapace 6rm and more or less compressed in the fore part,soft in the hinder part. Fourth pair of legs unlike the third. Rostrum almost or quitewanting. Pagurinea.II. Abdomen bent under the thorax. Body crab-like. Carapace firm all over. Fourth pair oflegs like the third. Rostrum spiniform. Lithodinea.EXPLANATION OF PLATE XLVILFig. L Huenia proteus, male of triangular shape; a. whole animal, b. part of the fine gravingof the back,greatly magnified.Fig. 2. Huenia j)roteus, female.Fig. 3. Naxioides spinigera, male ; a. whole animal, b. outside of hand, c. hooked hairs of twodifferentshapes.Fig. 4. Halimus espiiiosus, male ; a. whole animal, b. outside of hand, c. end-joint of a walking leg,d. hooked hairs.Fig. 5. Lambrus (^Rhinolambrus) turriger ; a. whole animal, b. part of under side to show groovesfor breathing stream. 1. endopodite of 3rd maxilliped, 2. exopodite of the same, 3. base ofepipodite of the same, covering opening to gill-chamber, 4. ridge on under side of body (notouter edge), 5. outer end of inner groove, 6. outer end of outer groove, 7. inner groove, 8. foreedge of mouth.Fig. 6. Lambrus {Aulacolambrus) sculptus ;part of inner groove corresponding to (7) in fig. 5,showing the covering of hairs.

Fauna and Geography, Maldives and Laccadives Plate XLVII£. W. del.BORRADAILEOXYRHYNCHA.

Fauna and Geography, Maldives and LaccadivesPlateXLVill< QoQ.

Now ready. Parts I— IV forming Voliune I.The Fauna and Geographyof theMaldive andLaccadive ArchipelagoesBeing the Account of the Work carried on andof the Collections made by an Expeditionduring the years 1899 and 1900J.Edited byStanley Gardiner, M.A.Fellow of Goiiville and Caius College and late Balfour Studentof the University of Cambridge.VOLUME I.With Plates I—XXV and Text-Illustrations i —119Cambridge :at the University Press.London :C.J.Clay and Sons,Cambridge University Press Warehouse,Ave Maria Lane.Glasgow : 50, Wellington Street.1903

7. Lepidoptera ... .;...... 123Volume I. of the above work is now complete and contains thefollowing Reports : PAGE1. Introduction : Narrative and Route of the Expedition. WithText-Figs. I and 2 1By J.Stanley Gardiner, M.A.2. The Maldive and Laccadive Groups, with Notes on other CoralFormations in the Indian Ocean. Chapters I—IV. WithPlates I and II and Text-Figs. 3—11 12By J. Stanley Gardiner, M.A.51By P. Cameron.3. Hymenoptera ...........4. Land Crustaceans. With Plate III and Text-Figs. 12—23 .By L. A. BoRRADAiLE, M.A., Lecturer in Natural Sciences of Selwyu College,'Cambridge.. 645. Nemerteans. With Plates IV and V 101By R. C.Punnett, B.A.6. Amphibia and Reptilia . . . . . . . . .119By F. F. Laidlaw, B.A.By Ed. Meyrick, B.A., F.Z.S.8. Echiuroidea. With Plate VI 127By A. E. Shipley, M.A.9. Sipunculoidea, with an Account of a new Genus Lithacrosiphon.With Plate VII 131By A. E. Shipley, M.A.10. Land and Freshwater MoUusca. With Text-Fig. 24 . . . 141By Edgar A.Smith.11. The Maldive and Laccadive Groups, with Notes on other CoralFormations in the Indian Ocean {continued). Chapters V—VII.With Plates VIII—XII and Text-Figs. 25—33 . . .146By J.Stanley Gardiner, M.A.12. On the Pigments of certain Corals, with a Note on the Pigmentof an Asteroid. With Text-Fig. 34 184By C. A. MacMunn, M.A., M.D.13. Marine Crustaceans. I. On Varieties. II. Portunidae. WithText-Figs. 35— :38 191By L. A. Borradaile, M.A.14. Chaetognatha, with a Note on the Variation and Distributionof the Group. With Plate XIII and Text-Figs. 39 and 40 . 209By Leonard Doncaster, B.A.15. Dragon-Flies 219By F. F. Laidlaw, B.A.........•••16. The Actinogonidiate Echinoderms of the Maldive and LaccadiveIslands 223By Prof. F. Jeffrey Bell, M.A.

CONTENTS.17. Orthoptera 234By Malcolm Burr, F.Z.S.,etc.18. Marine Crustaceans. III. The Xanthidae and some other Crabs.With Text-Figs. 41—60 237By L. A. BORRADAILE, M.A.............19. On the Fishes from the Maldive Islands. I. Dredged. II. Freshwater272Tate Regan, B.A.By C.20. The Marine Turbellaria, with an Account of the Anatomy ofsome of the Species. With Plates XIV and XV and Text-Figs. 61—73 282By F. F. Laidlaw, B.A.21. The Maldive and Laccadive Groups, with Notes on other CoralFormations in the Indian Ocean {continued). Appendix A.With Plates XVI and XVII and Text-Figs. 74 and 75 . . 313By J.22. Cephalochorda.Stanley Gardiner, M.A.I. Systematic and Anatomical Account. With Plate XVIII andText-Figs. 76—89 347By C. FoRSTER Cooper, B.A.II. Note on Meristic Vai'iation in the Group . . . . 361By R. C. PuNNETT, M.A.23. Aves 368By H; Gadow, M.A., F.R.S., and J. Stanley Gardiner, M.A.24. The Earthworms of the Maldive and Laccadive Islands . . 374PAGEBy Frank E.Beddahd, F.R.S.25. The Maldive and Laccadive Groups, with Notes on other CoralFormations in the Indian Ocean {concluded). Appendices Band C. With Plates XIX—XXI and Text-Figs. 90—109 . 376By J.Stanley Gardiner, M.A.26. Marine Crustaceans. IV. Some Remarks on the Classificationof the Crabs. V. The Crabs of the Catometope Families.VI. Oxystomata. VII. The Barnacles. With Plate XXIIand Text-Figs. 110—119 424By L.A. Borradaile, M.A.27. Marine Crustaceans. VIII. Stomatopoda, with an Account ofthe Varieties of Gonodactylus chiragra. With Plate XXIII . 444By W. F.Lanchester, M.A.28. The Lithothamnia of the Maldives and Laccadives. With PlatesXXIV and XXV 460By M. FosLlE.

It was supposed that the whole work would be completedin eight parts, forming two volumes, but it is now anticipatedthat one or more supplementary parts may have to be issuedeach part will contain about 120 pages of text, demy quarto,and will be fully illustrated by lithographic plates and textillustrations prepared by Mr Edwin Wilson of Cambridge.The edition is limited to 475 copies and the subscriptionfor the whole work including any supplementary parts thatmay be issued is for the present ;^4 45. net. The separate partsare published at 155. net.FORM OFSUBSCRIPTION.Messrs C. J.Clay & Sons,Cambridge University Press Warehouse,Ave Maria Lane, London.Please send me -cop ofThe Fauna andGeography ofthe Maldive and Laccadive Archipelagoesprice £^\a^s. per copy {incliidiug any siipplcincntary parts). Thework to be forwarded in separate parts on publication.Name ,...__..Address ,Date_To M.

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