4 J. H. ~CHUURM S STEKHOVE 1.1 R.

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1 INTRODUCTION(*) In the last decade numerous rese'arches have been made on the freeliving marine nemas of both the North Sea and the Baltic, so that nowadays we are fairly well informed upon the nemic fauna of that region. The nemic fauna of the Mediterranean however is very insuffieiently known and we possess of that region only sporadic data, as the result of a few superficial studies of that sea. I need to remember only to what has been done by EBERTH, RouviLLE, MARION, DE MAN, MICOLETZKY, KREIS STEI ER, CoBB, ZuR STRASSEN, TuERK and ScHuLz being rather sure to have strived therewith all studies on the nemic fauna of this very interesting region, one of the most important traffic ways of the. old world C). Therefore each gap, which may be filled up in our knowledge of this almost unknown field, is wellcome. Now fortunately orne very interesting collections of freeliving marine nemas, collected at different localities of this sea, which is the doorway to the Indies, touching at one side to the Atlantic, giving entrance at the other end to both the Sea of Marmora and the Black Sea and by means of the Canal of!suez to the Red Sea, were sent to me for study. Over these collections I hope to report in a near future ( 2 ). The most important of these collections, ( ) The manuscript of the systematical part had been finished already as early as the end of The finishing touch to the figures and the introduction was closed in the beginning of 1942, since I found not sufficient time before that date to put the manuscript in ~o final shape. January 18th (') The results of these studies were published in Mediterranean freeliving Nematodes II Camarque III Balearic, Pityuses (Mededeelingen Leyden Museum and in 1943, IV freilebende marine Nematoden der Fischereigriinde bei Alexandrien. Zoologische Jahrbii.cher, 1943 : respectively). (') In 1942, after the manuscript was sent to the editor ALLGEN published his : Die freilebenden Nematoden des Mittelmeeres : His own researches concern freeliving marine NematodPn of Banyuls-sur-Mer. For those who are interested I refer to this paper as it was impossible to take full account of this paper during the corrections of the printing proofs, 20th Dec. 1949, see page 23.

2 4 J. H. ~CHUURM S STEKHOVE 1.1 R. originated from Villefranche, and wa ollected by Dr. E. L E L O P. «Con r vateur a l'institut royal des Scien ce n aturelle de Belaique», during hi tay at the station of Villefran che in Prof. Dr. V. VA TRAE LEN, Dir ctor of the Institute did entrust m e this collection for further tud, for which opportunity I will thank him very h eartily at thi' place. The collec tion embrace no le of which 81 are n ew lo cience. than 614 specim n belon o in a lo 144 p ci To give an idea of ' hat h as bee n performed on Lhi. field of r ::; arch T "ill give a list of all peci found up lo lhe pres nt dale in th 1cdil crranea n, lh c species in que tion arranged in the famijie lo which the. ought le be r ec k 11 d. Order E OPLOIDEA. Family LEPT OSO MAT IDJE. 1. Anticoma acuminat'l (EBERTH}, Nice, aple, di ffer ent l ocalities i n the Adria, Banyul, Cett e, M allor ca, I bizn., Al exandria. 2. Anticoma leptura (MARION}, Mar eille. 3. Synonclms {asciculalus COBB, Naples. 4. Synonchus hirsutus COBB, 'aples. 5. Synonchus str asseni TUERK, aple. 6. Platycoma cephalata COBB, Naples. 7. Thor acostoma echinodon MARION, Marseille. 8. Thoracostoma steineri M I COLETZKY, aple, Alexandria. 9. Thoracostoma {iguratum (BASTIAN}, ice, Marseille, Napl es; according to ALLGE.~ (1942), synonymous with TIL coronalm11 (EBERTH} like Th. echinodon 1\IARION and Tit. coronatum V rllot. 10. Thoracostoma monlredonense MARION, Marseille. 11. Thoracostoma dorylaimus MARION, 1\Iarseille. 12. Thoracostoma zolre MARION, Mar eille, Alexandria. 13. Thoracostoma coronatum (EBERTH}, izza 14. Thoracostoma globi.caudatum SCHNEIDER, Si cily, Messina. 15. Cyl'icolaimus jaegerslrji.ildi (TUERK}, ::"\aple. 16. Le]Jlosomatum bacillatum (EBERTH }, Nice, aples. 17. Leptosomatum punctatwn (EBERTH}, i\ice. Family OXYSTOMATIDJE. 18. H atalaimus gracilis DE MAN, Adria, Rovigno. Bocche di Cattaro, Sea of Marmara. Family PHANODERMATIDJE. 19. Phanoderma gracile DE MAN, Naple 20. P hanoder ma mediterranea MICOlEfZKY, Adria, Banyuls. 21. Phanoderma aberrans MICOLETZKY, Adria. 22. l 'hmwderttw latico/lt' (l\1ar IO'i}, 1tu- ille,. lexantll'ia. 23. Phanoderma l u/jerculaltwl (EBEnTII }, :"\ice, Me ina. 21. f>iwiiodeti/iu sc/igerwn ( IAHIO\ },! UJ'>ieille. 1-tunily ENOPLIDJE. :!3. ll'iiojjiiis slrialu EUERTif, 'ic, 1\le. sina, Banyuls. 26. Enoplus l!irtus (MARION}, Mar eille, en. or Marmara. 27. E1lOJIIUs lllillll ' ( IARIO'i}, Marseille. 28. Enoplus olltusicaudatus EBERTH, Nice. 29. Enoplus meridiana/is TEI\ER, Teneriffa, Alexandria. lbiza. 30. Enoploides ilalicus TEJ\ER, \ dria. 31. yringolaimlts striaticatulalus DE 1\IA\. \dria. Rovigno, Ombla Bay, Bocehe tli Cattaro, I cilia, ea of Marmara. Family ONCHOLAIMIDJE. 32. Paroncholaimus parpapilli{erus llcoletlky, Adria, Bocche di Cattaro, Banyul. 33. Pelagonema simple.r COBB, Ischia, Rovig:no. 34. Jl ela]laroncholaimus campylocercu (DE ~la\, aple. 35. Viscosia glabra (13A TIA~ ). Xaples, Ischia. Rovigno, Bocche eli Cattaro, Jel eda. Ombla Bay, Alexandria, lbiza, Banyul Prooncholaimus megasloma (EBERTH, :\ice. aple, I ch ia, Adria, Rovigno, Oml.Jla Bay, Bocche di Cattaro. 37. Prooncholaimus tllcrlilerraneus Cll R'JA\ STEKHOVEN ( = f>t001lci!oifli111us 1/ll'[j(IS/IJ/1111 MICOLETZKY, nee EBERTil }, aples, Alexandria. 38. Oncholaimu clujardini DE MA'i, Naples, Cette, I chia, Adria, Rovigno, Ombla Bay, Bocche di Cattaro, Alexandria, Mn.llorca, Ibiza, Banyuls. 39. Oncholaimus papillosus EBEEITH, Nice, aples.

3 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN Onchola"imus arrnatus von DADAY, Fiume. 41. Metonchola imus pr"istiums (zur SrRASSEN), Naples, Cette, Banyuls. 42. Metoncholaimus demani (zur STRASSEN), Naples. 43. llasculonema cmruleum EBERTH, Nice. Family ENCHELIDIIDJE. 44. Eurustomatina ornatum EBERTH, Nice, Fiume, Rovigno, Banyuls. 45. Eurystomatina spectabile MARION, Marseille. 46. Enchelidium acuminatum EBERTH, Nice, Naples, Iscl1ia, Adria, Meleda, Rovigno. 47. Enchelidium bierstedti (MARION), Marseille. 48. Enchelidium marinum EHRENBERG, Nice. 48. Enchilidium paradoxum (MARION), Marseille. 50. Enchelidium eberthi DE MAN, Naples. 51. Enchelidium e.rile (MARION), Marseille. 52. Enchelidium subrotundum (EBERTH), Nice. 53. Symplocostoma pauli (MARION ), Marseille, Naples, Ischia,?"Rovigno, Meleda, Bocche di Cattaro. 54. Symplocostoma tenuicoue DE MAN, Cette, Marseille, Banyuls. 55. Bolbella co /Jbi MICOLETZKY, Adria, Rovigno. Order CHROMADORIIDEA. Family CYATHOLAIMIDJE. 56. Paracanthonchus s teueri (MICOLETZKY), Naples, Adria, R ovigno. 57. Paracanthonchus arcuatus KREIS, Taormina. 58. Praeacanthonchus med"iterraneus MICOLEI ZKY, Cette. 59. Praeacanthonchus guarneriensis von DADAY, Fiume, questionable species. 60. Longicyatholaimus longicaudatus (DE MAN), Naples, Alexandria. 61. Cyatholaimus gracilis (EBERIH), Nice Marseille, Naples, Cette, Messina, Sea of Marmara, Banyuls. 62. Cyatholaimus canariensis STEINER, Teneriffa, Mallorca. 63. Cyatholaimus prinzi (MARION), Marseille. 64. Cyathola imus oculatus (MARION), Marseille. 65. Cyatholaimus strialipunctatus (MARION), Marseille. Family DESMODORIDJE, 66. H eterodesmodora Naples. varioannulata KREIS, 67. H eterodesmodom ditlevseni MICOLEIZKY, Naples. 68. Monoposthia costata DE MAN, T eneriffa, Messina, Ibiza, Banyuls Aculeonchus sphaericus KREIS, Naples, Banyuls. 70. Acanthopharynx perarmata (MARION), Marseille, Naples, Ibiza canthopharynx micans (EBERTH), ;.lice, Marseille, Naples, Rovigno, Sea of Marmara, Banyuls. 72. Acanthopharyn;r; a{{inis MARION, Marseille, Mall orca. 73. Laxus contortus COBB, Naples. 74. Spirina parasiti{em (BASTIAN), Cette. I think ALLGEN (1932, p. 440) is right in considering Desmodora angusticollis DADAY and Desmodora papillata DADAY as questionable species. They are not considered here. Family CHOANOLAIMIDJE. 75. Demonema rapax COBB, Naples. Family CHROMADORIDJE. 76. Spiloplwrella mediterranea MICOLETZKY, Ischia, Adria, Rovigno, Ombla Bay, Bocche di Cattaro, Camarque, Banyuls. 77. Chromadorina parva (DE MAN ), T eneriffa, Adria, Rovigno, Melecla, Ombla Bay, Bocche di Cattaro, Banyuls. 7tl. ChTomadorina lmta (DE MAN ), Naples, Quarnero, Rovigno, Ombla Bay, Sea of Marmara, Banyuls. 79. Chromadorita magna ScHULZ, Messina. 80. Euchromadoru. loricata (STEINER), Naples, Bocche di Cattaro, Taormina. 81. Euchromadora striata (EBERTH), Nice, Fiume. Naples, Ischia, Adria, Alexandria, Sea of Marmara, Black Sea, Banyuls. 8" Rhabdodotoderma morstatti (MARION), Marseille. 83. ProchromadoreUa neapolitana (DE MAN), Naples, Adria, Bocche di Cattaro, Alexandria. 84. ProchrornadoreUa mediterranea (MICOLET ZKY), Adria, Rovigno, Meleda, Ombla Bay, Ragusa, Bocche di Cattaro, Mallorca. 85. Dichrom.adora parapcecuosoma (MICOLETZKY), Camarque, Adria, Meleda, Ombla Bay, Alexandria, Bocche di Cattaro, Sea of Marmara. 86. Dichromadora pcecilosornoides (FILIPJEV), Messina, Banyuls.

4 6 J. H. SCHUURMANS STEKHOVEN JR. 87. Paroxystom'lna asymmetr ica MTCOLETZI<Y, Rov igno, Bocche di Cattaro, Meleda. 88. Chromadora qt~adtil'inea FILTPJEV, Naples, Adria. 89. Chrornadora chlorophthalma DE MAN, an insufficiently lmown species, after AUgen (in litteris synonym with C. nudicapitta, Naples). 90. Chromadora nudicap'itata BASTIAN, Cette, Quarnero, with vvhich apart from C. chlorophthalma, Chrmnadora flamon iensis VON DADAY and Chro11Wdora quarneriens'ls von DADAY should by identical, Banyuls. 91. ChromadoTella membtanata MICOLETZI<Y, Adria.. Family DRACONEMATIDJE. 92. Draconema claparedei METSCHNIKOFF, Naples, Salerno. 93. Draconema cephalatum COBB, Naples. 94. Draconema ophiocephalwn CLAPAREDE, Saint Vaast. 95. DTaconema micoletzkyi KREIS, Taormina. 96. Draconema tristichoch<eta PANCERI, Ischia, Naples. 97. Draconema long'lrost-rum ScHEPOTIEFF, Naples. 98. Draconema mactocephalum SCHEPOTIEFF, a pies. Family EPSILONEMATIDJE. 99. Proch<Etosoma cygnoides (METSCHNIKOFF), Naples. Family COMESOMIDJE Sabatieria cettensis DE ROUVILLE, Cette. Order ARJEOLAIMOIDEA. Family AXONOLAIMIDJE Ar<Eolaimus bioculatus (DE MAN), Naples, Adria, Rovigno, Cattaro, Alexandria Ar<Eolaimoides mediterraneus (DE MAN), Naples, Ischia, Adria, Rovigno, Meleda, Ombla Bay, Bocche di Cattaro Metarawlaimoides oxystoma DE CONINCI<, Sardinia Diplopeltis cirrhatus (EBERTH), Nice, Naples, Banyuls. Family CAMACOLAIMIDJE Ionema isseli MICOLETZKY, Rovigno, Meleda, Bocche di Cattaro, Banyuls. Family HALAPHANOLAIMIDJE ieg'laloala'lmus tenuis (KREIS), Naples. Order MONHYSTEROIDEA. Family LINHOMOEIDJE Linhomreas obtas icaudatus DE MAN, Adria, Rovigno, Melada, Ombla Bay, Bocclle di Cattaro, Banyuls Metal inhomreus elegans KREIS, aples. Family MONHYSTERIDJE Pcuamonhystera patanonnand ica (MICOLET ZKY), Adria, Rovigno, Ombla Bay, Bocche di Cattaro, l'iaples, Ischia. Alexandria "1-l etataimus gracilis KREIS, Naples Rhabdocoma macrutum COBB, Naples Monhystera macrolabiata KREIS, aples Mohhystera heteropa-rva MICOLETZI<Y, Adria l\lonhystera patva DE MAN, Adria TheTistus izhor icus (FILIPJEV), Mes ina. Family SIPHONOLAIMIDJE S'lphonotaimus niger DE!VIA, aples Siphonolaimus weissmann'l (zur TRASSE:-<), aples Siphonolaimus nigticans (COBB), Naples Solenola'lmus obtasus COBB, 'aples. Order DESMOSCOLECOIDEA. Family DESMOSCOLECIDJE Desmoscolex 11rinutas CLAPAREDE, Brindi i. Naples Desmocolex adtiaticus SCHEPOTIEFF, Rovigno, Brindisi, Naples Desmoscolex l<evis KREIS, Taormina Eudesmoscolex ch<etogastet (GREEFF), 'apies T'ricoma nematoides (GREEFF), aples Tricoma cincta COBB, Naples. Family GREEFFIELLIDJE Gree{{iella oxyca udata GREEFF, Naples, Ischia, Salerno, Rovigno. Order ANGUILLULOIDEA. Family TYLENCHIDJE Halenchus mediterraneus Adria, Rovigno, Meleda, Cattaro, Banyuls. (MICOLETZKY), Bocche di

5 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 7 During my studies of the freeliving marine nematodes of the Baleares, Alexandria. and the Camarque I observed the following forms : Order ENOPLOIDEA. Family LEPTOSOMATIDJE Anticoma pellu.cid.a BASTIAN, Alexandria Leptosomatum longiseta SCHUURMANS STEK HOVE, Alexandria. Family OXYSTOMATIDJE H alalaimus longicauda ALLGEN, Mallmca Tre{usia filum SCHUURMANS STEKHOVEN, Mallorca. Family PHANODERMATIDJE Phanodenna albidum BASTIAN, Alexandria, Banyuls. Family ENOPLIDJE Enoplas littoral-is FILIPJEV, Alexandria, 134. Enoplus {lagellicaudatus SCHUURMANS STEK HOVEN, Alexandria Enoploides longisetosus SCHUURJIIANS STEK HOVEN, Alexandria. Family DORYLAIMIDJE Syringolaimus brevicaudattts MICOLETZKY, Alexandria Doliclwlaimus nudus SCHUURMANS STEKHO VEN, Alexandria Doryla inws filifonnis llastian, Alexanch ia. Family ONCHOLAIMIDJE Oncholaimus paroxyuris SCHUURJIIANS STEK HOVEN, Camarque Oncholairnus brevicaudatus FILIPJEV, Alexandria, Blacl< Sea Oncholairnellus mediterraneus SCHUURMANS STEKHOVEN, Mallorca Viscosia langrunenis DE MAN, Alexandria Viscosia palm<e SCHUURMANSc STEKHOVE!'l, Mallo rca Viscosia cobbi FILIPJEV, Alexandria Viscosia <Egy pt'ica ( STEI~ER ), Alexandria Anoplostoma v iviparum DE MAN, Canrarque Mononcholaimus elegans KREIS, Camarque. Family ENCHELIDIIDJE Eurystomatina terricola (EBERTHJ, Mallorca Eurystomatina assimile {DE MAN), Alexandria, Black Sea, Fiume, Naples Symplocostoma marioni FILI PJEV, Alexandria Symplocostoma ponticum FILIPJEV, Alexandria, Sea of Marmara, Black Sea Conistomella brev icaudata SCHUURMANS STEKHOVEN, Mallorca Bradystoma longisetosum SCHUURMANS STEK HOVEN, Alexandria Bolbella alexandri<e SCHUUR!\<IANS STEKHOVEN, Alexandria. Order CHROMEDOROIDEA. Family CYATHOLAIMIDJE Cyatholaimus paragracilis SCHUUR IANS STEKHOVEN, Mallorca Cyatholaimus demani FILIPJEV, Alexandria, Black Sea Paracyatholaimus choanotaimo ides SCHUUR MANS STEKHOVEN, Mallorca Metacyallwlaimus hirschi SCHUURJIIANS STEKHOVEN, M allorca Paracanthonchus micoletzlcyi SCHUURJIIANS STEKHOVEN, Alexandria Paracanthonchus elongatus (DE MAN), Alexandria. Family DESMODORIDJE Desmodora pontica FILIPJEV, Alexandria Metadesmodora arnphidiscata SCHUURJIJANS STEKHOVEN, Mallorca Acanthopharynx micramphis SCHUURJIIANS STEKHOVEN, lbiza Acanthopharynx setosissima SCHUURJIIANs STEKHOV&'l, Alexandria. Family CHROMADORIDJE S pilophorella euxina FILIPJEV, Mall orca Dichromadora microdonta l{reis, Mallorca Chrornadora brevipapillata MICOLETZKY, 168. Pareuchromadora setifer n. sp., Alexandria. Alexandria, Mallorca Chromadorina gracilis FILIPJEV, Alexandria, Black Sea Hypodontolai11ws ponticus FILIPJEV, Mal!orca, Black Sea Hypodontolaimus monodon SCHUURJIIANS STEKHOVEN, Camarque. Family MICROLAIMIDJE ~lli crolaimus obtusicauda SCHUURJIIANS SrEK HOVEN, Alexandria. Family COMESOMIDJE abatietia hilarula DE MAN, Mallorca Sabatieria tenuicaudata (BASTIAN), Alexan dria.

6 8 J. H. SCHUURMANS STEKHOVEN JR. Or der ARJEOLAIMOIDEA. Pamily HALAPHANOLAIMIDJE Halaphanolaimus minutus SCHUURMANS STEKHOVEN, Mallorca EgiaLoaLaimus tenuicaudatus ALLGEN, Mallorca. Family CERAMONEMATIDJE PseUonema annulatum (FILIPJEV), Mallorca, Family TRIPYLOIDIDJE TTipyLoides deman i FILIPJEV, Camarque, Black Sea BathyLaimus assimil'is DE MAN, Camarque. Order MONHYSTEROIDEA. Family LINHOMOEIDJE MetaUnhomreus ef{uatus SCHUURMA S STEK HOVEN, Mallorca PamLinlwmreus amphilabiatus SCHUURMANS STEKHOVEN, Mallorca Linhomreus macramphis SCHUURMANS STEK HOVEN, Mallorca ELeutherolaimus elegans SCHUURMANS SrEK HOVEN, Mallorca Sph<eTOCephalum bulbi{em SCHUURfllANS STEKHOVEN, Alexandria. Pamily MONHYSTERIDJE MonllysleTa capitata SCHUURMANS STEKHO VEN, Mallorca il'lonhystem mictocephalon SCHUURMANS STEKHOVEN, Mallorca Theristlts oxycetca DE MAN, Canlal'l]Ue. Family SIPHONOLAIMIDJE. 18. Si.phonoLaimus cyundticaudalus ScHUUR!\JAN STEI(HOVEN, Camarque. Fa111ily SPHJEROLAIMIDJE. 18!J. SphceTola imus gtacius DE MAN, Canmrque. Order ANGUILLULOIDEA. Pamily RHABDITIDJE Rlwbdilis monhyslera BUETSCHLI,.\lexanclria. Order DESMOSCOLECID Pamily DESMOSCOLECIDJE Tricoma nernaloides (GREEFF), Mallor ca :f1 icoma septuaginla SCHUUH~IANS TEKHO- VEN, Mallorca. Moreover some other species of doubtful position and sy lemalic affinil; are known from this region, which, like the foregoing summary as well a lhe present study shows is particularly rich in forms. From a zoogeographical point of view, the nemic fauna of lhe Mediterranean shows no peculiar resemblance to the nemic fauna of both Baltic and North Sea. Up to 1935, at the moment ScH RMA s STEKIIOVE publi h d hi summary on the freeliving nematodes of Iorth Sea and Baltic, these ea had only 27 species in common with the Mediterranean. Since then thi number has risen to 41, that is on the 190 species, known up lo thi dale from lhe mediterranean 24,5 % and 13,6 % from the 299 pecie known in 1935 from North!Sea and Baltic. That means, that although we may take into con ideration that our knowledge about the ematodes of Torlh Sea and Baltic ha been enlarged in different ways, so as by the newer monograph of LLGE ' (1935) on the Nematodes of the Oeresund, smaller papers of the same author on several localities of the Coast of Norway, as well as by the third Monograpl1 of ScHUURMANS STEKHOVEN (1935) on freeliving Nematodes of the Belgian Coast, the percentage of forms, which North Sea and Baltic at one side and the Mediteranean at the other side have in common remains small and is inconsiderable in comparison with the forms found either exch1sively in that sea, or in that

7 FHEELIVING MARI NE NEMAS OF THE MEDITEHHANEAN ea and in Lhc seas, adjacent or n eighbouring to the 1editerranean, like the Black Sea, the Sea of Azov, the Sea of Marmora and the Red Sea. W e have also to think at intruders from the Coa st of North Africa as valuable elem ents '~r hi c h might have contributed to Lhc composition of the n emic fauna in the M cd iterran ean. A clear insight in Lhe composition of the n emic faun a of the Meditteranean will n ot be possible before m ore is known about the nemic fauna of the Atlantic Coas t from Portugal and Spain and about the Iorth Coast of Africa. After h avin g treated the nemic fauna of the Bay of Villefranche and Lilong I hope to com e back on the geographical aspect of that faun a. To begin with I m ay point to the fact, that the biocoenoses, although rich in forms, a wellkn own fact, known to a1l who have m ade studies on that field in the Mediterranean, had a very low nemic index, opposite what has all ways been emphasized by FILIPJEv ( ) and ALLGE ( ), who r epeatedly h ave stated, Lhal the Amphiox us-ground is a rich breeding-ground for n emas. Tn Villefranche and Lilong the following species have been found. Those that are n ew for Lhe Mediterranean are marked with an asterisk. Order ENOPLOIDEA. Family LEPTOSOMATIDtE. 1. Leptosomatum baciu.aturn E BERTH. 2. T lwracostorna steineri MICOLETZKY. 3. Anticorna peuucida BASTIAN. *4. Anticoma insulce-alb<e FILIPJEV. 5. A 11 ticoma acuminata (EBERTH). *6. tenolai1ttus paralepturus 11. sp. "7. tenolairnus metagracilis 11. p. *8. tenolairnus brevicauda 11. sp. 9. Halalaimus g racilis DE MAN. *10. Trefusia longispiculosa BRESSLAU etschuurll'lans STEKHOVE!'i. Family PHANODERMATIDtE. 11. Phanoderma ditlevseni F I LIPJEV. "J2. Phanoderma nasuturn n. sp. 13. Phanoderma laticolle (MARION). *14. Phanodenna parasiticum DITLEVSEN. "15. Phanoderma elegans n. sp. *16. Galeonema longicauda n. sp. Famiy ENOPLIDtE. 17. Enoplus merid ionalis STEINER. *1. illesacanthion tricilsjyis 11. sp. 19. Enoploides amphioxi FILIPJEV. 20. Oxyonchus dubius F I LIPJEV. Family DO RYLA I M I DtE. 21. Dolichotaimus nudus SCHUURMANS STEKHO VE~. *22. Anoncholaimus rhopalurus n. sp. 23. Oncholaimus dujar dini D E M AN. 24. Onchotaimellus mediterr aneus SCHUURMANS S TEKHOVE.'I. *25. Filipjevia rnediterr anea n. sp. 26. M etoncholairnus pristittrus (zur S TRASSE ). 27. Metoncholaimus demani (zur STRASSEN). 28. Pr ooncholaimus mediterraneus n. sp. 29. Viscosia glabra D E MAN. "30. Viscosia elongata F I LIPJEV. "31. riscos ia br achytaima F ILIPJEV. 32. T"iscosia rnacrorhopalocer a K REI S. 33. Mononcholaimus etegans K REI S. Family ENCHELIDIIDtE. "34. BoLbeUa hexabulba FILIPJEV. *35. Par eur ystomatina tenuicaudata n. sp. 36. Eu-r.ystom.atina or natum (EBERTH ). "37. Eur ys tomatina stenocaimmn n. sp. *38. SymplocostomeUa meditetranea 11. sp. 39. Enchelidiurn acumi.natum EHERTH. *40. Enchelidium longicolle F I LIPJEV. 41. Encllilidium JJauli (M ARION). 42. Catal airnus eberthi ( DE M AN). *43. Symptocostoma paratenuicoue SCHUUHJ\JANS STEKHOVEN. *44. Symplocostoma filicauda n. sp. "45. Symplocostoma Longicolle BASTIAN. "46. Symplocostoma longiseta n. sp. Order CY ATHOLAIMOIDEA. Family CYATHOLAIMIDtE, *47. Longicyatholaimus {ilicaudattts n. sp. "48. Longicyatholaimus e{{ilatus n. sp. *49. 1\l etachoniolaimus pustulosus 11. sp.

8 to.t. H. SCHUURM ANS STh KHOVEN JR. *50. Metachonio!a irnus cy!indribucca n. sp. *51. Pam!ongicyatlw!a imtts mastigodes n. sp. *52. Cyatho!airnus pauc ispim n. sp. *53. CyatlJOlairnus ch'itwoodi n. sp. ''54. Parasew atieua brev iseta n. sp. *55. Praeacanthonchus rnicoletzkyi n. sp. *56. Praeacanthonchtts angulatus n. sp. *57. Praeacanthonchus ttni{onnis 11. sp. *58. Pamcanthonchtts {ili1jjevi MICOLETZKY. Family CHOANOLAIMIDJE. *59. Cobbionerna cylindrola irnoides n. sp. *60. Cheironchus macramphis 11. p. *61. Trogolairnus micrarnphis 11. sp. 62. Halichoanolairnus filicauda FILIPJEV, Banyuls. Family DESMODORIDJE. 63. Desrnodora pontica FILIPJEV. *64. Desrnodora macrarnphts n. sp. "'65. Desmodora coniseta n. sp. *66. Pamdesrnodom cephalata n. sp. 67. Heterodesmodom ditlevseni. MICOLETZKY. 68. Acanthopharynx perannatu (MARION). "69. Acanthoplwrynx rigida n. sp. *70. Acanthopharynx seticauda n. sp. *71. Croconerna longiseta n. sp. "72. Spirina rouviuei n. sp. *73. Chromaspirina paucispi'i"l n. sp. *74. Metachrornadom longilaima n. sp. "75. Metachrornadora papiuata n. sp. Family MONOPOSTHIIDJE. *76. Monoposthia mediter-ranea n. sp. Family RICHTERSIIDJE. *77. RichteTSia elongata n. sp. Family CHROMADORIDJE. 78. Spi!ophoreUa euxina FILIPJEV. 79. Spi!ophoreUa rnediterranea (MICOLETZKY). *80. Euchromadora a{ricana VON LrNsrow, further Teneriffe. *81. Euchromadora in{latispiculum n. sp. 82. Hypodontolaimus ponticus FILIPJEV. *83. Dichromadom tenu icauda n. sp. *84. Dichromadora punctata n. sp. "85. ProchromadoreUa brachyura n. sp. *86. Trichromadora ophiocephala n. sp. Family COMESOMIDJE. *87. Dory!aimopsis punctatus DITLEVSEN. *88. Paracomesorna coronata n. sp. "89. Comesoma JJUnctata n. sp. 90. Sabatieria hilarula DE MAN. *91. Sabatieria Longicaudata FILII'JEV. *92. Sabat'ieria al.iyssal'is FILII'JEV. *93. al.ia.t'ieria cla.v icauc/.a FILII'JEV. *94. Sal.iatieria rugosa n. sp. *95. Sabatieria e{filata 11. sp. Order ARLEOLAIMOIDEA. Family DIPLOPEL TIDJE. *96. D'iplopelt'is cirrhatus (EBERTH ). Family AXONOLAIMIDJE. 97. Arceola inm Vioculatus (DE MAN). *98. Arceeolaimoides demani n. sp. gg_ A.conotaimus arcuatus n. p. "100. Axonolaimus JJOnticus FlLIPJEV A.conolaimus spec. *102. Odontophom quadristicha 11. p. *103. Odontophom breuiseta 11. r. <'104. Odontophom angustilaima (FrLIPJEVl. Family HALAPHANOLAIMIDJE. "105. ~outhernia elongata n. p. Family TRIPYLOIDIDJE. *106. Bhal.idocoma breuicauda n. p. "107. Bhabdocoma cylindricauda n. SJJ. "10. Paratripyloicles longicaucla n. sp. Order MO HYSTEROIDEA. Family LINHOMOEIDJE. < 109. MetalinhOIIIC tts l.ireuisela n. p. *110. Metalinlwmreus cytinclricauda 11. Sjl. "111. Metalinhomceus attenuatus II. sp i\.l eta/inhomreus e{{ilatus CHU R~JA.\S 1EK- HOVEN. "113. Metal'inhomceus oblusicauc.l.atu ( DE l\ia\ J. "114. i\1 e talinhomceus pilosu n. p. *115. Paralinhomre us etongatus 11.!J. *116. Paralinhomrens clauicaudatus 11. p Paralinlwmreus ostrearum Fll.IPJEV. *118. Paral'inhomreus brevicauclatus 11. sp. "119. Paralinlwmreus breuibucca 11. sp. *120. Perilinhomreus longisetosus 11. sp. *121. Parachromogasteriella conicaucla ll. SJ!. *122. Terschellingia hetero eta 11. sp. "123. TerscheUingia antoiloui FILIPJEV. *124. Eteutherolaimus duplicatus n. Sjl. "125. Omicronenw truncatum 11. sp. Family SPHAEROLAIMIDJE. "126. Sphcerolaimus dispar FILIPJEV. *127. Sphcerolaimtts macrocirculus FILIPJEV. Family SIPHONOLAIMIDJE Siphonotaimus weissmanni (zur STHASSEN).

9 FREELIVI 1 G MARINE NEMAS OF THE MEDITERRANEAN 1 t Family MONHYSTERIDJE Paramonhystera paranormandica (Mrco- LETZKY ). "130. Paramonhystera euiptica FILIPJEV. "131. Paramonhystera rnicramphis n. sp. "132. Theristus mieoticus FILIPJEV. "133. Theristus tenuispicu~um OITLEVSEN TheTistus normandicus (DE MAN), Banyuls. *1:35. Theristus longicaudat us FILIP.JEV. *136. Theristus calcaneus n. sp. ''137. Theristus angu~atus n. sp. *138. Theristus stichotricha n. sp. *139. Theristus obtusicepha~atus n. sp. "140. Metadesrno~airnus coronatns n. sp. *141. Monhystera gracilicauda n. sp. *142. Monhystera hetero~aima n. sp. *143. Monhystera tenuis n. sp. *144. LinhomceUa tenuicauda n. sp. Of these 143 species 106 are new for the Mediterranean, so that the number of species, known from that Sea amounts to 297 species, indeed a very rich output compare further page 23. The Mediterranean has delivered us some new data about species formerly found in the North Sea and Baltic only. The said species are the numbers 1, 3, 10, 14, 36, 45, 87, 90, 91, 134 from the list, beginning on page 9. In total the Mediterranean has now 51 species in common with the North Sea and Baltic, that is on the 299 species known in 1935 from North Sea and Baltic, no more than 17,1 %. One should however not forget that the number of pecies known from 1 orth Sea and Baltic has increased considerably by the researches of ALLGE so that we may be rather sure that the percentage of forms the North Sea and Baltic have in common with the Mediterranean, lays not over 15 % of the species occurring in that region. Like mentioned above the percentage the Black Sea has in common with the Mediterranean is considerably greater than that which the North!Sea and Baltic have in common with the Mediterranean. If I speak of percentages this percentage should be taken on the whole fauna of the Black Sea. Up to this moment we do know from the Black Sea, the 'Sea of Azov and the Sea of Marmara, which may be considered as a zoogeographical unit not less than 147 species. From these 147 species 23 occur in the Sea of Marmara, which as far as our knowledge reaches has only 2 species in common with the Black Sea : Euchromadora striata (EBERTH) and Oncholaimus dujm dini DE MA. From the Black Sea proper FILIPJEV (1918, 1921, 1922) has described 115 species, whereas he enumerates for the Sea of Azov 15 species, of which 4 are likewise found in the Black Sea. These 4 mean so much that the Sea of Azov has 26,6 % of its nemic fauna in common with the Black Sea. If we Lake the 147 species of the Sea of Marmara, the Black Sea and the Sea of Azov together and compare this fauna with the nemic fauna of the Mediterranean we get the following data. From the 23 species found to occur in the Sea of Marmara, this Sea has 15 species in common with the Mediterranean, i.e. not less than 65 %. If we take the Black Sea proper we find that from the 115 species found till so far

10 i2.t. H. SCHUURMANS STEKHOVEN JR. in the Black Sea proper 34 occur likewise in the Mediterranean or 29,5 % of the Black Sea nemic fauna. From the Sea of Azov with its 15 species we know that 5 or 33,3 % occur likewise in the Mediterranean. Do we take the three 1Seas together than we get on a total of 147 species this region possesses 51 species or 34,7 % occuring likewise in the Mediterranean. It is clear I think that the Mediterranean shows greater affinities with the Black Sea, the Sea of Marmara and the Sea of Azov than with more northern European Seas. It forms a zoogeographical territory in itself, receiving specie from neighbouring seas. On which way this occurs cannot be stated with certainty. I suppose that traffic plays an important role in the di tribution of the concerned nematodes. Ships may transport together with many epont, that generally are growing on their skin, nematodes too and so we may ea il~r explain why the Mediterranean has so many forms in common with the mentioned seas. Floating algae may also serve the ame purpose. From the foregoing data may be concluded, that the Blacl ea Fauna represents an empoverished Mediterranean FQ.una. The explanalion for I his phenomenon lays at hand. It is found, that the Black ea with it compara tively great depths has a rather high salinity in its deeper layer. On the e layers of high salinities the effluent of the rivers, flowing in the Black ea build sheets of lower salinity. The hydrological circum lances are in the Black Sea as a whole I think less favourable for the development of a rich fauna than elsewhere, certainly less favourable than in the Mediterranean. o it i no wonder that the nemic fauna too is poor in comparison with that of the Mediterranean. The Black Sea is a place of selection for those specie, that can live in rather high salinities. I suppose the rever e takes pia e in that region of what we find for instance in the former Zuid ersea with il low salinity. Here we likewise encounter an empoverished marine nemic fauna. Its components partly are recruted from the high Sea, being euryhaline forms, that can withstand a rather high dilution of the seawater, partly typical form, of brackish water and brackish soil. That habitat ha likewise made a election but on the other sid e of the scale. In both cases we have to do with an inland sea, in the case of the Zuidersea with an inland sea of low in the ca e of the Black Sea and the Sea of Azov with an inland sea with at least partl high salinities. Both circumstances result in the empoverishment of the inhabiting fauna. To get a concise id ea about the forms the Sea of Marmara, the Black ea as well as the Sea of Azov h ave in common with the Med iterranean I will summarize the mentioned forms in the following Tables.

11 FREELTVING MARINE NEMAS OF THE MEDITERRANEA f TABLE 1. Species the Mediterranean has in common with the Sea of Marmara. Number of species known from that Sea : 23. A ntcoma acum'inata (EBERTH ). 9. Euchromadora striata (EBERTH). tlalalaimus gracil'is DE MA. 10. Chromadorlna l<eta ( DE MAN). :~. Enoplus lt irtus MARION. 11. Dichromadora paraprecilosoma (MICOLETZKYJ. ' Oncholaimus dujardini DE MAN. 12. Arreolaimus mediterraneus ( DE MAN). 5. llfetoncholaimus pristlurus (zur STRASSEN). 13. Metalinhomreus obtusicawlatus ( DE MAN). G. ymplocostoma ponticwn FILIPJEV. H. Paramonhy s tera paranormandica (MICOLET 7. Cyatholaimus gracilis (EBERT H). ZKY}. 8. tl canthopharyn:c micans (MAR ION}. 15. Theristus normandicus DE MAN. TABLE 2. Species the Black Sea has in common with the Mediterranean. Total of species known from the Black Sea : tep/osonwturn bacillatum (EBERTH }. 18. Chromadorina yracil'is FILIPJEV. 2. h'/10]1//ls /'it/ora/is f'ii. IPJF.V, 19. 'piloplwrella eu:rina FILIPJEV. :1. Eno11loides amphioxi FJLIPJEV. 20. Hypodontolai1tlUs ponticus FILIPJEV. ' Oxyonchus dubius FILIPJEV. 21. Euchromadora striata (EBERTH}. 5. Oncholaimu brevicaudatus FILIPJEV. 22. abatieria longicaudata FrLIPJEV. 6. Oncholairnus dujardini DE MAN. 22. abatieria abyssalis (FILIPJEV}. 7. Metonchola'imus dernani (zur STRASSEN abatieria clavicauda (FILIPJEV}. Bolbella hexabulba (FILIPJEV}. 9. Enchelidiurn longicolle FILIPJEV. 25. Diploppeltis cirrhatus (EBERTB). 26. Axonolairnus ponticus FILIPJEV. 10. Enchelidiurn pauli (MARION). 27. Odontophora angust'ilaima (FILIPlliv). 11. ymplocostoma longicolle BASTIAN. 28. Pselionema annulaturn (FILIPJEV}. 12. ymplocostoma ponticurn FILIPJEV. 29. Tripyloides demani FILIPJEV. 13. Eurystomatina assimile (DE MAN}. 30. Paralinhomreus ostrearum FILIPJEV. 14. Cyatholairnus demani FILIPJEV. 31. Pararnonhystera elliptica FILIPJEV. 15. Paracanthonchus filipjevi MICOLETZKY. 32. Theristus longicaudatus FILIPJEV. 16. Halichoanolaimus {ilicauda FILIPJEV. 33. Sphrerolaimus dispar FILIPJEV. 17. Desmodora ponlica FILIPJEV. 34. phrerolaimus macrocirculns FILIPJEV. TABLE 3. Species the Sea of Azov has in common with the Mediterranean. Total of the species found in the Sea of Azov : 15. J. Enoplus litloralis FIUPJEV. 2. l'iscosia glabra (BASTIAN}. :t Anoplostoma viviparum (BASTIAN). 4 TersciieUingia antonovi FILIPJEV. 5. Theristus mreoticus FILIPJEV. Undoubted! future re earches will prove that the mentioned ea shmy an even greater similarity in their composition than the present study has brought to light. We tay so to ay at the beginning of the exploration of the nemic fauna of the Mediterrauean with its adjacent seas. The general trend of the result of these future researche will however remain the same. row I come to the composition of the nemic fauna at the various habitats near Villefranche and in the Bay of Lilong.

12 .T. H. SCHUURMANS STEKHOVEN.TR. Gare fj;~ /'1;r/n,;n-J i/ l/'"' IB ~~i' ~ BAlE c; \\ DE 1 4 IB {. ' /) VILLEFRANCHE <.LJ... '. ~ /.e:... (~: /i 'II "'~! ' ~.:' \. r. j '._)... I/ ; ]..-:'..., Av~~~ (. r(;;~!f. \ \ ~ (;' IO \.':~ ~2E 1\ ll ~ ~.. >~ \. /.. ~ >t,o; - d~.-:j ~ ~ ~ /....(_' '') ill~: >.,,-... ~~ /.rz.i'rp! ~ ~, i., -:r. -< vp.'. ~ (.: :.. li f ~ - ',;) '... \' \ -jji k ~ )T ~-\~ "" /"lj~ j.,....- \ ': //e;lr ~,/,/ - ~/ > [./, _. '\ ~ [.... ; ~. -~.>,~~~- /, "":",, ~~vi; o'.,- ' ">./,_ ~.-, \ v v 8>7 B\ \... l 1. -\ t7.\ :{( :~ \ ~; ~,_.. \ ',. \ \.. I'.,_ ', ~ ~~-- ~ : \~ \ '\. JJA.,.,., ' \ -. ~~<"""' -...,,'. \, r : t- ', i' ~ ///My I ( /. Map of the Bay of Villefranche (Stations 1 B-7 B) and the Bay of Lilong (Stations 1 A-2 A).

13 FREELIVI G MARINE NEMAS OF THE MEDITERRANEAN 15 Sample 1 A. " Baie de Lilong " coarse sand, depth 3m, quantity 94 cc, 82 nematodes, 10 species, nemic index 0,87. SPECIES lcr I % I 9 I % I Juv I T otal /% of total ]. Metoncholaimus demani (ZUR STRASSF.N) Galeonema longicauda n. sp ,22 3. Oxyonchus dubius FrLIPJEV ,22 4. Dolicholaimus nudus SCHUURMANS STEK HOVEN ,22 5. Oncholaimus dujardini DE MAN ,22 6. Cyatholaimus paucispira n. sp ,22 7. Spirina rouviuei n. sp ,22 8. Paracomesoma coronala n. sp ,22 9. Hypodontolaimus ponticus FILIPJEV , Viscosia brachylaima FrLIPJEV ,22 Metoncholaimus demani is by far the leading species. The nemic index in itself is low. Apparently this kind of habitat is no good breeding ground for nemas. In the Zuidersca media with coarse sand often did harbour a comparatively large number of species, but the number of each species was very low, a parallel to what we find here. Metoncholaimus demani is known to feed on Syna cidia. We have no certainly if it feeds on other nematodes, but should this be the case, it would give an explanation for the predominance of the species, compare likewise sample 1 B. Sample 2 A. " Baie de Lilong " coarse sand, with shells, depth 5 m, quantity of material 140 cc, 73 nematodes, 23 species, nemic index 0,52, therefore very low. SPECIES lcr I % I 9 I '/'o I Juv. I Total I %of total 1. Euchrom.adora a{ricana von LIN STOW , ,1 2. Anticoma acurninala (EBERTH) ,4 6 54, ,8 3. Viscosia glabra (BASTIAN) H Pararnonhystera paranormandica (Mrc.) ,4 5. Acanthopharynx rnicans MARION ,4 6. Prooncholaimus rnediterraneus n. sp ,1 7. Syrnplocostorna longicoue BASTIAN ,7 8. Pr<Eacanthonchus uni{ormis n. sp ,7 9. Pr<Eacanthonchus {i{lifpj evi MICOLETZKY ,7 10. Spilophorella euxina FILIPJEV J ,7 11. Dichrornadora tenuicaudata n. sp ,7 12. Draconerna, ponticurn FruPJEV ,7 13. Hypodontolaimus ponticus FILIPJEV ,7 14. Halalairnus gracilis DE MAN , Phanoderrna elegans n. sp , Eurystomatina stenolaimum n. sp , Enchelidium longicolle FILIPJEV , Catalaimus eberthi (DE MAN) , Symplocostoma paratenuicolle n. sp , A r<eolaimoides demani n. sp , Thoracos toma steineri MrcoLETZKY , Desmodora pontica FILIPJEV , Theristus m<eoticus FrLIPJEV ,35 I - -- Total number of specimens : 73 2

14 t6 J. H. SCHUURMANS STEKHOVEN JR. When compared with sample 1 A it becomes at once clear that none of the 23 species occupies a dominating position. I have the impression that we have here to do with a phenomenon often observed in the Zuidersea, that on certain spots, where the bottom consists of coarse sand, and the medium does not afford optimal conditions for the development of a rich nemic fauna, where thirdly flood and ebb are felt, many species are swept together from their original breeding ground and now hide in the bottom, being sieved out by the fine openings the sand presents. In such cases, like in the present case, the majority of the species i represented by single specimens, whereas there is a di proportion between adults and juveniles. In the same habitat I found Cumaceae, foraminifers, shells. Among the first three species, which together form the majority of the nemic biocoenosis Anticorna is an epont, frequently occurring an hydroid. Sample 1 B. Villefranche " Plage des Marinieres " under Vegetation of Posidonia, depth 3 m, Amphioxus sand, coarse sand. Quantity of material 70 cc, 55 nematodes, 22 species, nemic index 0,78, therefore rather low. SPECIES lcr I % I <;? I 'X I Juv. I Total J 'Yo of total 1. Oncholaimus dujardini DE MAN ,1 3 42, Antico'ma acuminata (EBERTH) ,9 3. Enorplus meridionalis STEINER Metalinhomceus obtusicaudatus (DE MAN) L eptosomatum baciuatum (EBERTH) ,4 6. Viscosia glabra (BASTIAN) a ,4 7. Thoracostoma steineri MrcOLETZKY ,6 8. Phanoderma ditlevseni FILIPJEV ,6 9. Enchelidium acuminatum (EBERTH) I 2 3,6 10. Enchelidium longicolle FILIPJEV ,1\ 11. H eterodesmodora ditlevs eni MICOLETZKY ,6 12. StenO'laimus paralepturus n. sp Stenolaimus brevicaudatus n. sp ,8 14. Phanoderma nasutmn n. sp ,8 15. Phanoderma laticolle (MARION) ,8 16. Enchelidium pauli (MARION) ,8 17. Prceacanthonchus micozetzkyi n. sp i,s 18. Acanthopharynx rigida n. sp i ,8 19. Diplopeltis cirrhaflus (EBERTH) Axonolaimus species ,8 21. Paralinhomceus clavicaudatus n. sp i i' 22. Euchromadora striata (EBERTH) ,8 --- Tolal number: 55 In the same biocoenosis I found Amphioxus, annelids. anisopods, isopods. The composition of the nemic fauna greatly resembles that of sample 2 A. It shows clearly that the coarse Amphioxussand, considered at the same time the low nemic index and the great number of forms, the majority of which is only represented by a single or a few specimens, not necessarily is a rich breeding place for Nematodes. Enoplus and Anticoma often are found as eponts in

15 FREELIVI G MARl IE NEMAS OF THE MEDITERRANEA i 7 colonie of Hydroids. They apparently likewise may live in the biocoenosis of Posidonia. From Oncholaimus dujardini we known that it feeds on colonies of Zoobothryon and eventually too on other ynascidia. Thus the main repre entants of the sample give an indication of the kind of biocoenosis they live in and upon. Sample 2 B. Taken off the Station, coarse sand under vegetation of Posidonia, depth 15 m. Quantity of material 60 cc, 23 nematodes, 14 species, nemic index 0,38, very low. SPECIES jd' I % I 9 I % J Juv. I Total I % of total 1. Desmodora macramphis n. sp Theristus mreoticus Fn.IPJEV Euchromadorra striata (EBERTH) Enoplus meridional is STEINER ,7 5. Comesoma punctata n. sp ,7 6. Metadesmolaimus coronatus n. sp ,7 7. Cheironchus macramphis D. sp ,3 Paradesmodora cephalata n. sp ,3 9. pirina rouviuei n. sp ,3 10. Monoposthia mediterranea D. sp ,3 11. Dichromadora punctata D. sp ,3 12. Sabatieria rugosa n. sp ,3 13. M etalinhommus pilosus n. sp ,3 14. Paralinhommus brevicaudatus n. sp , 3 We have here before u a similar biocoenosis as that of sample 1 B, although it compo ition is different. There is no domination at all of one of the component and the great many pecie of which we find some few pecimen only indicate that the habitat is no favourable breeding ground for nema, Juvenile are almo t totall ab ent. That speak likewise against a thrifty life of the nematode in question.

16 18.T. H. SCHUURMANS STEKHOVEN JR. Sample 3 B. Black mud and organic detritus, further end of the " Port de la Darse»; depth 3 m, 33 nematodes, 26 species. Quantity of mud 160 cc, nemic index 2,06 the highest nemic index found at all near Villefranche. SPECIES 1. Corne soma coronata n. sp Tersch.eUingia antonovi FILIPJEV Sabatieria clavicauda n. sp Theristus normandicus (DE MAN) Meta~inhmnmus breviseta n. sp Longicyatho.~aimus ef{uatus n. sp ' Sabatieria ~ongicaudata FILIPJEV Th. eristus angu~atus n. sp Metoncho~aimus pristiurus ZUR STRASSE!'l. 10. Anticoma insu~m - a~bm FILIPJEV Oncho~aim.cllus mediterraneus SCHUUR- MANS STEKHOVEN Viscosia g~abra (BASTIAN) Hypodonto~aimus ponticus FILIPJEV Mononch.o~aimus e~egans KREIS Meta~inhommus cylindricauda n. sp Monhystera gracilicauda n. sp Cheironchus macramphis n. sp Viswsia e~ongata FILIPJEV Acanthopharynx seticauda n_ sp Trichromadora ophiocepha~a n. sp Metalinhommus ef[ilatus SCHUURMANS STEKHOVEN Paralinh.mnms e~ongatus n. sp Theristus calcaneus n. sp Metalinlwmmus obtus icaudatus FILIPJEV. 25. Hali c hoano~aimus {ilicauda FILIPJEV Desma dora macramphis n. sp I (J I % I c;? I % I Juv. I Total I% of total ,8 41., , , , J :1 : ,2 58, ,8 25 :14, , i '1 J : ,2 6,6 4,8 5,6 2,~ 2,'1 2,1 1,8 1,~3 Total : 334 specimens '' ~~ ' The material is a mixture of mud and sand.!stones are intermixed ' ith it. It presents ferrireduction. The black colour indicates that we ha e to do with ferrosulfurous mud, which is almost deprived of oxygen. Here we g t quite another picture of the development of the nemic fauna. In the present case we are able to speak of a thrifty nemic fauna, rich in species as well a in individuals and characterized by a significant reproductive activity of the leadin ()' forms. The presence of a great quantity of organic detritus is respon ible for that phenomenon, for we know, that many species of nematodes feed on particles, bacteria, as well as detritus, that is small enough to pas the oral aperture of the animals in question. CoBB has shown at earlier occa ion that the bulk of the nematodes lives in the upper 10 mm of the bottom mud. Th e density of the nematode population, which was over 2 per cc and was the highest found near Villefranche, remains however small and inconspicuous in comparison with the nemic population formerly found by the writer in the Zuidersea, where at some spots nematodes per cc were collected. Compared with these localities even the richest nematode biocoenosis near Villefranche remains poor. The present sample proves once more that it is 1,43 1,43 1,2 o.~ 0,9 0,6 0,6 0,3 0, ,3 0,3 0,3 0,3 0,3 0,3

17 FREELIVI G MARl E 1 EMAS OF THE 1EDITERR 1 EA 1 19 not the Amphioxusground for itself that is a rich breeding ground for nemas, but mudcontaining bottom with a rich content of organic detritus that has to be considered as such. Sample 4 B. Black mud and organic detritus, off " Vieux Villefranche». of mud 150 cc, 156 nematodes, 21 species, nemic index 1,04, depth 20m. SPECIES lcr I % I 9 I Quantity % I Juv. I Total I % of total 1. Crocanema Longiseta n. sp : ,8 2. abalieria clavicauaa FILIPJEV : : ,4 3. TerscheUingia antonovi FILIPJEV ,8 4. Paracome oma corona/a n. sp ,1 3 42, ,7 5. Desmodora macramphis n. sp ,4 (i. Metonchotaimus pristiurus Z UR STRASSEN ,2 7. Oaontophora quadrislicha n. sp ,9 Paramonhyslera elliptic a FILIPJEV ,9 9. Mo"nhystera heterotaima n. sp ,9 10. Viscosia gtabra (BASTIA ) ,6 1 33,3-3 1,9 11. Anticoma peuucida BASTIAN , ymptocostoma LongicoUe BASTIAN , Prreacanlhonchus angutatus n. sp , Therislus tongicaudatus f'ilipjev '1, Anticoma acuminata (E BERTH) , Eurystomalina ornatum (EBERTH) , Euchromadora in{ latispicutum n. sp ,63 1. outhernia elangata n. sp , M elatinhomreus brevis eta n. sp , ParaLinhomreu ostrearum FILIPJEV , Paralinhomreus Longisetosus n. sp i i --- Total number: :156 The composition of the ample 4 B shows great resemblance with that of ample 3 B and is of the arne type. The nemic ihdex is somewhat lower and thi may depend on the greater depth of the sea at this spot. The smaller quantit of available oxygen rna play probably an important role in the den ity of the population and the rate of reproduction. But for the rest we get here a there orne pecie which produce off pring and are at home in the g-iven habitat. In the material I found Cumaceae as well a fibre.

18 20 J. H. SCHUURMANS STEKHOVEN JR. Sample 5 B. Villefranche, between the " Lazareth, and " Anse passable», depth 50 m. Quan~ity of mud 112 cc, 26 nematodes, 42 species, nemic index 0,67. Consistence of mud : very fine, mixed with sand. SPECIES I d' I % I <.;? I % I Juv. Total / % of total I 1. Metachromadora longilairna n. sp ,8 2. Sabatieria hilamla (BASTIAN) ,5 3. Stenolairnus paraleptums n. sp ,2 4. Paraseumtiella breviseta n. sp ,8 5. Halichoanolairnus filicauda FILIPJEV ,8 6. Desrnodom coniseta n. sp ,8 7 Dorylaimopsis punctatus DrrLEVSEN ,8 8. Terschellingia antonovi FILIPJEV ,8 9. Sphrerolaimus dis par FILIPJEV ,8 10. Trefusia longispiculosa BRESSLAU-S. S ,6 11. Viscosia rnacrorhopalocera KREIS ,6 12. Longicyatholairnus fi!icaudatus n. sp ,6 13. Desrnodora macrarnphis n. sp ,6 14. Richtersia e~ongat(h n. sp i 50 ' ,6 15. Hypodontolairnus ponticus FILIPJEV ,6 16. Siphonolairnus weissrnanni (Z. SrRASS&'<) ,6 17. Phanoderrna parasiticurn DrTLEVSEN ,3 18. Filipjevia rnediterranea n. sp ,3 19. Bolbella hexabulba (FILIPJEV) ,3 20. Syrnplocostornella rnediterranea n. sp ,3 21. Syrnplocostoma filicauda n. sp i 1,3 22. Syrnplocostorna longiseta n. sp ,3 23. Metachoniolairnus pustulosus n. sp '1,3 24. Chrornaspirina paucispira n. sp ,3 25. Spi~ophorella rnediterranea (MrcOLETZKY) ,3 26. Euchrornadora inflatispiculurn n. sp ,3 27. Prochrornadorella brachyura n. sp i ,3 28. Sabatieria clavicauda FILIPJEV i - - i 1,3 29. Sabatieria etfilata n. sp i 1,3 30. Axonolairnus ponticus FILIPJEV i 1 1,3 31. Odontophora breviseta n. sp ,3 32. Odontophora angustilairna n. sp ,3 33. Rhabdocoma brevicauda n. sp Paratripy~oides longicauda n. sp ,3 35. Metalinhornceus attenuatus n. sp ,3 36. Eleutherolaimus duplicatus n. sp i 1 1,3 37. Theristus longicaudatus FILIPJEV ,3 38. Theristus stichotricha n. sp ,3 39. Theristus obtusicephalus n. sp ,3 40. Monhystera tenuis n. sp ,3 41. Linhorncella tenuicauda n. sp ,3 42. Cobbionema cylindrolaimoides n. sp ,3 Although the habitat in question has given the largest output in pecie, we must consider the biocoenosis as a poor one. Let us put for instance the first three or 4 species together than they make out no more than at the utmost 27,3 % of the whole biocoenosis or no more than 23,5 % of the biocoeno i, if we take only the first 3 species together. One gets the impression, that the given habitat is no good breeding place. This fact becomes obviou if we compare sample 5 B with 4 B, where the first three species together make out 69 % of the biocoenosis and we therefore find, notwithstandig the fact. that the nemic index is comparitively low, an outstanding domination of orne species, which may be considered as representative for the fauna at that locality.

19 FREELIVI G MARl E NEMAS OF THE MEDITERRA 1 EA 1 2f In the pre ent ca e it is hardly po ible to peak of repre entative forms. Secondly the nemic inde i low. This become ea ily explainable if we take in account the fact, that the con i tence of the ub trate i not very favourable for a thrift biocoeno i. The quantity of mud i far in the minority in compari 011 with the and, ' hich i intermixed with the mud. That means that the quan lit. of food, which for the main part con i t in fine or()'anic detritu, i clefi i nt. Further l may point to the fact that Sphrerolairnus dispar and Halichoanolaimus dispar, two nematodes of which we know that they prey on other nematode too-ether make out 7,6 % of lhe fauna, and althou()'h thi a a ' hole i not den e, it may b a factor of orne importance in checking the reproduc LiYit of other form. ample G B. Villefranche, off the " Pointe de la Gavinette " grey mud, depth 0 m. Quantity of material 116 cc, very fine mud, 128 nematodes, 35 species, nemic index 1, SPECIES lcr I % I 0 I % I Juv. Total I I %of Lotal 1. Dorylaimopsis puncta/us DITLEVSEX ,6 9 64,4 : ,3 2. abatieria abys alis FILIPJEV ,2 3 42, ,6 3. abatieria hilarula (BASTIA.'I) ,7 4 36, ,5 4. Hypodontolaimus ponlicus FILIPJEV ,4 5 55, Anticoma pellucida (BASTIAN) ,3 4 66, ,2 6. pilophorella ell.'xina FIUPJEV ,2 3 42,8-7 5,4 7. phrerolaimus dispar FILIPJEV ,6 tenolaimus paralepturus n. sp ,:1 9. tenolaimus metagracilis n. sp ,1 10. Rhabdocoma cylindricauda 11. sp ,1 11. Mesacanthion tricuspis n. sp ,3 12. Metachromadora longuaima n. sp ,6 1 33,3-3 2,3 13. Paramonhystera macramphis n. sp ,3 14. Pareurystomatina tenuicauda n. sp : Paralongicyatholaimus masligodes n. sp ,5 16. Cobbionema cylindrolaimoides n. sp ,5 17. Ax011olaimu arcuatus n. p ,5 1. Rhabdocoma brevicauda 11. sp ,5 19. Theristus normandicus ( DE 1\IA:'\) Enoploides amphioxi FILIPJEV ,7 21. Anoncholaimu rhopalurus n. sp : ,7 22. Vis costa brachylaima FILIPJEV ,7 23. Cyatholaimus chitwoodi n. sp ,7 2-i. Trogolaimus macramphis n. sp DesmodO'ra pontica FILIPJEV ,7 26. Desmodora macramphis n. sp :1 1 0,7 27. M etachromadora papillata n. sp ,7 2. abalieria clavi cauda FILIPJEV :1 - - I 0,7 29. Paralinhomaws brevi bucca 11. sp ,7 30. Parachromoga teriella coni cauda n. sp ,7 31. Terschellingia hetero eta n. p ,7 32. Theri tu tenuispiculwn DITLEVSEX :1 0,7 33. outhernia elongata 11. p :1 0,7 3i. Halalainw gracilis DE l\ia:'\ ,7 35. :iphonolaimu w ei smanni ZuR TRA EX ,7 Total number : 128

20 22 J. H. SCHUURMANS STEKHOVEN JR. It is a remarkable fact, that three Comesomidae occupy the three first places of the list. Now unfortunately the mode of feeding of these Comesomidae is not known. The only thing of importance is that Dorylaimopsis punctatus has protrusible teeth, so that we may suppose that these serve a carnivorous m ode of feeding. This does not apply for Sabatieria however. For the rest the composition of the biocoenosis is similar to that of sample 4 B and 2 A, in which case we too have some species, that are present in a rather high percentage, forms, that do reproduce, without occupying a dominating place in the biocoenosis. Here again the biocoenosis is rich in forms without in it elf being a rich breeding place, because the nemic population is not dense, confer the low nemic index. Sample 7 B. Villefranche, entrance of the road, grey mud, depth 230 m, fine mud. Quantity 140 cc, 12 nematodes, nemic index 0,08. SPECIES icr I % I 9 I % I Juv. j Total I %of total 1. Sabatieria abyssalis FILIPJEV ,6 2. Sabatieria clavicauda FILIPJEV ,6 3. Theristus tenuispiculum DITLEVSEN ,6 4. MesacanthiOn tricuspis n. sp ,3 5. M etachoniolaimus cylindribucca n. sp ,3 6. Sabatieria hilarula (BASTIAN) i Sphrerolaimus dispar FILIPJEV ,3 8. Sphrerolaimus macrocirculus FILIPJEV ,3 9. Dorylaimopsis punctatus DITLEVSEN ,3 Total : 12 I further found Cumaceae at this spot. There is no predominance in this biocoeno is. In its composition it i very alike the foregoing sample 6 B, only that it is much poorer in specie and at the same time less dense. One gets the impression that with increa ina depth the nemic index becomes lower and the nemic population le den e. The decomposition of fine organic detritus possibly has proceeded in higher water layers already so far, that only a comparatively mall percentage of the original available quantity reaches the abyssal depths. So the greater depth like that of sample 7 B afford bad conditions for the production of a rich nematode population. This observation does not stay apart. I have made Lhe same experience during the examination of the nematode material of the Snellius expedition e). Here samples of mud from abyssal depth were ( 3 ) This paper treating about 150, mostly new species will appea1 as a communication of the Leyden Museum of Natural History in Temminckia, to which it was presented in 1944.

21 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 23 available. Many of these were quite free from nematodes. In general the nemic index was small in the samples taken during that expedition. The majority of the nematodes captured during that expedition originated from low depths, almost without exception habitats from the littoral zones, in the coral shelves of the islands. In the same way we see in the neighbourhood of Villefranche that a more luxurious nemic fauna is found in the littoral zone. The nematodes found in greater depths like those found in sample 7 B are supposed to be transported to there from the littoral zone, therefore to a spot, which in itself is no good breeding place but where the nematodes in question are able to prolong their life for a certain span of time. Resuming what the study of the concerned biocoenoses has learned us, we may say : i. The Amphioxus-ground may be rich in species, but generally has a low nemic index, is no rich breeding ground. 2. Only in the case the biocoenosis contains a rather great quantity of organic material, we find a comparatively high nemic index. 3. With increasing depth the nemic index increases, which makes us conclude that. because in abyssal depths the quantity of available organic material is low the nematodes are generally bound to the littoral wnes. 4. The nematode faunas of Mediterranean, Sea of Marmara, Black Sea and Sea of Azov belong to the same zoogeographical area. Probably traffic plays a great part in the distribution of nematodes as also may floating algae. Many species are bound in their distribution to this zoogeographical unit. ALLGEN (1942) moreover mentions from Banyuls the following species further to not found in the Mediterranean (compare p. 10) : 298. Leptosomatum sabangense STEINER (?) Phanoderma para{uipjevi ALLGEN Oncholaimus viridis BASTIAN Pelagonema obtusicauda FILIPJEV Pelagonerna tenue KREIS (P. propinque ALLGEN) Syringolaim.us striaticaudatus DE MAN Paracanthonchus c<bcus (BASTIAN), Cette, Banyuls Parachanthonchus ophtha~mophorus STEI- NER Cyatholaimus sunesoni ALLGEN Hypodontolaimus :::osterm ALLGEN Hypodontolaimus heymonsi (STEINER) Spilophora gracilicauda dolichura DE MAN Spilophora kryptospiculum ALLGEN Euchromadora m.editerranea ALLGEN Pareuchromadora fragilis (Al.LGEN) ChromadoreUa fui{ormis (BASTIAN) AUgenieUa tenuis (G. SCHNEIDER) Chromadora paramucrodonta ALLGEN Microlaimoides weberi ALLGEN (Linhomoeid) Armolaimus elegans DE MAN Armolaimus cobbi STEINER Ar<Bolaimoides microphthalmus DE MAN, Bany uls, Sardinia, Capella, Balai Odontophora paratenuicaudata ALLGlt'i Camacolaimus tardus DE MAN Monhystera gracilis DE lvhn, Cette, Banyuls Monhystera ambigua DE MAN, Banyuls Monhystera paratenuispiculum ALLGEN M onhystera macqueriensis ALLGEN Eleutherolaimus leptosoma DE MAN Paralinhommus lepturus DE MAN Paralinhmnmus Longicaudatus ALLGEN. I give this list without further criticism, although I do not in all respects agree with ALLGEN's identification. Neither did I take account of the percen-

22 24 J. H. SCHUURMA 'S STEKHOVE ' Jn. tages already calculated at an earlier date, which, due to the present inve ligations of ALLGEN will undoubtedly undergo orne change, although the general trend remains the same. Finally DE CoNI ' CK wrote orne papers concerning Mediterranean ematodes after the manuscript ' as sent to pre, whi h contain ome ne' specie. (1936, 1937, 1942 A and B) which pecie I will enumerate here : 329. llletarreolamo"ides oxystoma DE C., Sardinia XeneUa s11ecica Au.GEN, Sarclinia, Oeresuncl Euch.romadora spec., Castiglione, Alger llletadasynemella macrophalla DE C., Beaulieu, l\ionaco Ceramonema ch.itwoodi DE C., Cap l\iartin,!\len ton Ceramonema filipjevi DE C., Beaulieu, Monaco Ceramonema undulatum DE C., Cap 1\Iartin, l\lenton. P elionema richardi DE C., 13 aulieu, l\ionaco,!\ienton. Pselionema simile DE C., Cap l\iartin,!\ienton, Beaulieu, l\ionaco. Pselionema simplex DE C., Beauli u, 1\Ionaco, Cap Martin,!\Ienton. Utrecht, 15 'ovember 19H.

23 THE FR.EELIVING MARINE NEMAS OF THE MEDITERRANEAN I THE BAY OF VILLEFRANCHE SYSTEMATICAL PART Order I : ENOPLOIDEA. FAMILY LEPTOSOlUATID.lE. Genus LEPTOSOMATUM BASTIAN, Leptosomatum bacillatum (EBERTH, 1863). (Fig. 1, A, B.) 3 juvenile specimens from Villefranche, off the " Plage des Marinieres,, coarse sand under vegetation of Posidonia. Depth 3 m. Unfortunately the original description of Leptosomatum bacillatum EBERTa given by thi author is very incomplete as are also his fiaures. We may however conclude from EBERTH's figure 1, which depicts the anterior end of a female with two eyes, that the specimen wa figured either from the dorsal or from the ventral side, otherwise one eyespot only should have been depicted. The socalled pores, which in reality are mall setae with their afferent nerveducts are depicted in this figure on both lateral sides and not on the surface which is directed against the observer. row all specimens of Leptosomatum as well as of Leptosom,atides possess rows of cervical or subcephalic etae at the lateral sides. It i essential to know ho' the amphids of the type specimens are constructed and in this we remain in doubt.

24 J. H. SCHUURMANS STEKHOVEN Jn. I wish to emphasize that the tail end bears likewise a number of similar papillar setae, which is es ential for our comparison ' ith related pecics. FILIPJEV ( ) gives in his monograph of the frecliving marin nemas of the Blach Sea a redescription of Leptosomatum bacillatum (EnERTH). A B A B 'i 'I I FIG Leptosomaturn baciualurn (EBERTH). FIG Thoracosloma steineri l\ircoletzky. A : Head of a juvenile. B : Tail of the same. A : Head of a male. B : Male tail. FIG Anticoma peuucida BASTIAN. A : Head. B : Tail of a female. In his description and figure we have to do ' ith a pecie with minulc subcephalic papillae on the lateral sides of the anterior end, papillae of minor length than those of the specimens from Villefranche and apparent! of minor length as well as compared with the specimens of the Black Sea. The amphicl are of markedly larger size than those of the pre ent pecimen, and what ma be of more importance even, the tail end of FILIPJEv's female did not pre ent the rows of papillae, which EBERTH's female presented. o I doubt if EBERTrr' species and that identified as such by FILIPJEV are in reality con pecific.

25 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 27 Neither am I quite convinced that the female identified by DE MAN (1885) as belonging to Leptosomatum bacillatum EBERTH did in reality belong to the said species. His figures are too poor to decide this question and as far as the description is concerned this may fit as well to that of L. bacillatum as to that of another species. There is however as to my opinion a rather great chance that DE MAN really had to do with the mentioned species. I have thought for a while that the present specimens might belong to Leptosomatides euxina FILIPJEV, but the tail of this species is decidedly shorter than that of Leptosomatum bacillatum. So I have come at last to the conclusion that my specimens of Villefranche are in reality specimens of the type species Leptosomatum bacillatum (EBERTH) and that the specimens kept for representants of that species by FILIPJEV ( ) do belong to another although closely allied species for which I propose the name Leptosomatum filipjevi. Dimensions : 1 juv. L. 9,5 mm; CL = 98,5; ~ = 6,85; y = 98, { P. The index ~ falls a little bit out of the range of variation of EBERTrr's species. Body tapering rather much towards the anterior end, long and slender. Head end bluntly rounded anteriorly. Head not set off by a special constriction. Head capsule faintly indicated. Anterior crown of labial papillae composed of 6 elements. Follows a crown of 10 cephalic papillae in the usual distribution. Further the anterior body end presents 6 longitudinal rows of subcephalic or cervical papillae, 2 lateral rows, and 4 submedian rows, extending to about the neighbourhood of the eyespots. These are situated on a distance from the anterior end, equal to 3,5 times the width of the head at a level with the cephalic papillae. Amphids minute, pouch-shaped, their slit not larger than 7 % of the cephalic diameter. Buccal cavity shallow, leading into the oesophageal cavity. Anterior end of the oesophageal cylinder distinctly swollen. erving at 26 % of the total length of the oesophagus. Along the oesophagus we find large cells filled with granules. These cells might be cuticular glands but apparently do not belong to the system of lateral field glands. Tail end cyiindrical, almost quite 1,5 times as long as the anal diameter. Apparently the tail bears the same number of longitudinal rows of papillae as the anterior end of the body and here too they are arranged more or less in such longitudinal rows.!spim1eret terminal, being the outlet of voluminous caudal glands. GEOGRAPHICAL DISTRIBUTION : Nice, Villefranche, Banyuls (ALLGEN, 1942), aples, Black Sea. ALLGEN (1940) mentions to have found it along the Norwe-

26 28 J. H. SCHUURMANS STEKHOVEN JR. g-ian Coast near Stappen. The tail of his female was however comparatively shorter, when in comparison -vvith its width; the head end is insufficiently depicted. His female from Banyuls misses, as far as it i not misfigured the rows of papilliform setae. Genus THORACOS'rOMA MARION, Thoracostoma steineri MICOLETZKY, (Fig. 2, A, B.) 1 r:f, 1 juv. from Villefranche, off the " Plage des Marinieres n, coarse sand under vegetation of Posidonia. Depth 3 m. 1 juv. from " Bai e de Lilong,, sand. Depth 5 m. Like the foregoing species Thoracostoma steineri is apparently a form occurring in shallow water. Just as in the case of Leptosomatum, Th. steineri is insufficiently known from the descriptions of my predecessors. Then unfortunately MICOLETZKY, which has studied also the male, has given no figures of a male specimen, which \ oulcl enable us an easy identification, since the differences in the males of different species are generally more pronounced than those in the females. Dimensions : r:f : 5,760 mm; 'J. = 51,5; ~ = 4,64; M y = 57, fj. Head end rounded anteriorly. Head capsule very vigorous. Oral open in (T rather small. Labial papillae distinct, 6 in number. A cro\ n of 10 eli tin l cephalic setae, 14,6 % of the corresponding cephalic diameter. Amphid pearshaped with a narrow posterior end, 23,7 % of the corresponding diameter. Oesophageal end of body with distinct lateral rows of subcephalic minul, papillae, the submedian papillae not quite arranged in rows. Eye pol at a distance from the anterior end equal to 2,93 times the length of the crphali capsule, which is 40 micra long. Terve ring at 37,2 % of the oe ophag al length. Tail with distinct caudal glands, the cell bodies of which have shifted to in front of the cloaca. Shape of tail bluntly conical, rounded po teriorly, quite as long as its anal diameter. The tail possesses a terminal row of 6 minute setae at each lateral side. Moreover we find 4 pairs of postcloacal elevations in 2 rows, each elevation crowned with a small seta, like this is the case in Th. trichodes (LEucKART, 1849). These rows do extend till far in front of the cloaca. Here we find in total 24 pairs of praeanal papillae, of which the 18 anterior ones bear no setae. I counted 30 bands of bursal muscles, which are closely adjacent in the present species and cover the same distance along the body as the praeanal warts. This distance equals 4,25 tail lengths.

27 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 29 Apart from the mentioned elevations we find a ventromedian wart, opposite to the proximal end of the spicula, separated from the cloaca by a distance only slightly shorter than the tail is long. The shape of the spicula is very peculiar. They are 1,34 times as long as the anal diameter. Their manubrium is rather narrow. Then the spicula widen greatly to the middle, whereas their distal end is again narrow and truncate. Gubernaculum vigorous with broad and blunt dorsal apophysis. Its distal end embraces the distal portion of the spicula for a great deal. As far as the genital armature is concerned the present species resembles rather much that of Synonchus strasseni TuERK. GEOGRAPHICAL DISTRIBUTION : Naples, Villefranche. ) have seen a female form Alexandria, Egypt. MICOLETZKY (1922) found it in!suez. ALLGEN (1942) says to have found the same species at Banyuls. His figures however miss accuracy. Genus ANTICOMA BASTIAN, Anticoma pellucida BASTIAN, (Fig. 3. A, B.) 2 cf cf, 4 Cj? Cj?, 2 juv. from Villefranche, off the " Pointe de la Gavinette,, grey mud. Depth 80 m. 1 Cj?, 1 juv. from Villefranche, off " Vieux Villefranche», black mud and organic detritus. Depth 20m. In my treatment of the nemas of the Northsea and the Baltic I did synonymize Anticoma acuminata (EBERTH) after the description of CoBB (1891) with Anticoma limalis BAsTIAN. Now that I myself have seen specimens of the Mediterranean, which undoubtedly belong to the same species as CoBB described, I feel compelled to revise my opinion and think now, that EBERTH's A. acuminata after the diagnose of CoBB has to be synonymised with A. pellucida BASTIAN. The main reason why I have separated A. pellucida BASTIAN from A. limalis BASTIAN was the difference in situation of the excretory pore in relation to the amphids and the cervical setae. row it appears that in the specimens of Villefranche, the excretory pore is situated just halfways the amphids and the anterior seta of the cervical group. And as for the amphids they are situated just like in the specimens studied by CoBB «half way between the cephalic setae and the pore». Remains the question if CoBB's A. acuminata (EBERTH) is conspecific with the A. acuminata of EBERTH, a question that is somewhat difficult to decide, because EBERTH does not mention the pore. There is however another difference between CoBB's and EBERTH's specimens which CoBB solves by saying : «Seemingly by a misprint, the neck was stated to be one third as long as the body». Now I have found in Villefranche what I consider to be the true Anticoma acuminata (EBERTH). In one of the males of that species measured by me the oesophagus was nearly quite 1/ 3 as long as the body length.

28 30 J. H. SCHUURMANS STEKHOVEN Jn. In these males, as well as in the accompanying females, the excretory pore was found on a level with the foremost of the group of cervical setae. So I come to the conclusion - which was likewise the result of my studies for «the freeliving marine nemas of the North Sea and Baltic >> - that A. pellucida BASTIAN and A. acuminata EBERTH ought to be considered as distinct species. DADAY's A. acuminata apparently belongs to the same species as the present female, confer the forward position of the vulva and the relative length of the oesophagus. Dimensions : <j? : 2,19 mm; a.= 42,1; ~ = 5,1; y = 7,8; v. = 49,2 % FILIPJEV's formula : fj.. Head bluntly rounded anteriorly. 6 minute labial papillae. 10 cephalic setae, nearly half as long as the corresponding body diameter. Opening of amphids 28,5 % of the corresponding body diameter, halfways between the cephalic setae and the excretory pore, which is separated from the anterior border of the head by not quite 1,5 times the cephalic diameter at the level of the cephalic setae. Cervical setae in one of the females arranged in 2 group composed of respectively 3 and 2 setae, separated from the foreborder of the head by a distance 2,5 times as long as the body diameter at the level of th, cephalic setae. A similar distribution was observed by MICOLETZKY (1924) in the specimens this author identified as A. acuminata EBERTrr. Female tail slender, 8,4 times as long as the anal diameter, slightly swollen at the tip, devoid of setae Anticoma insulre-albre FILIPJEv, (Fig. 4, A, B.) 1 cf, 2 <j? <j?, 2 juv. from Villefranche, black mud and organic detritus farther end of the " Porte de la Darse " Depth 3 m. Dimensions of a cf : Length 3,11 mm; '1. = 40,5; ~ = 5,5; y = 18,2. FILIPJEv's formula : M P Frr.JpJEv's cf : Length 4,56 mm; a. = 35; ~ = 8; y = 30. It is with some hesitation, that I bring the specimens from Villefranche to FILIPJEv's A. insulce-albre, although there are many points in common, the dimensions of the mediterranean specimens are considerably smaller, a feature not uncommonly observed when arctic specimens of a certain species are

29 FREELIVING MARINE NEMAS OF THE MEDITERRANEA_ 3t compared with representants of the same species from more southern latitudes. Moreover there is a rather great difference in the index y. At the other hand my specimens from Villefranche have so many points in common with FxLIPJEv's F 8 4 A Fra Anticoma insulre-albre FILIPJEV. FIG Anticoma acuminatum (EBERTH). A : Male head. B : Male tail. A : Male head. B : Male tail. C : Male genital armature. FIG Stenolaimus paralepturus n. sp. A : Female head. B : Female tail. C : Female head end. D : Female tail. E : Male head. F : Male tail. specimens of A. insulre-albre, that I feel justified in bringing the present specimens to A. insulre-albre better than to create a new species for them. The specimens in question are characterized by the backward position of the 3

30 32.T. H. SCHUURMAN~ STEKHOVEN JR. excretory pore, the irregular grouping of the cervical setae, just like in the type specimens, and by the fact, that shape and relative position of the spicula towards the praeanal tubulus, the shape of the tail as well as the distribution of caudal and praecaudal setae of the specimens of Villefranche are identical with those in the type specimens. Anterior portion of the body tapering. Head rounded anteriorly, labial papillae distinct. 10 cephalic setae, the longer ones measure 75 % of the corresponding cephalic diameter. Cephalic portion distinctly set off again t the remainder of the body, quite adjacent to the amphids, the opening of 'i hich measures 23,5 % of the corresponding body diameter. Cervical setae eparatcd from the anterior border of the head by a distance equal to 2,1 % the bod diameter at the level of the cephalic etae. Ierve rin o at 46 % of the whol oesophageal length. Excretory pore not far from the nerve rino at 71 % of the distance between the anterior end and the nerve ring or lio'htl. po terior to the anterior limit of the last praeneural third of the oesophagu. Spicula arcuate, their chorn 1,5 times as long a th anal diam l r. Gubernaculum small. Praeanal tubulus at a level with the pro 'imal end of th spicula. There are 2 submedian ro> s of rather di tin t prae audal eta. which are composed of 6-7 praeanal and 1-2 po tanal setae. Ther fore a h row is composed of 8 to 9 setae in total. Tail, 4 anal diameter long, ba al fourth conical, followed by a cylindrical flagellum, be et 'i ith orne irreo'ularl: scattered setae. Lower lip of cloaca prominent. From A. trichura CoBB (1898) to which the pre ent pecie how ~ om resemblance it differs i.a. by the more forward po ition of the excreter, por, the smaller size of the amphidial opening and the more backward po ition of the praeanal tubulus Anticoma acuminata (EBERTrr, 1863). (Fig. 5, A C.) 1 juv. from Villefranche, off " Vieux Villefranche " black mud and organic detritus. Depth 20m. 5 cf cf, 6 <;> <;>, 2 juv. from " Baie de Lilong " near Villefranche. Depth 5 m. 2 <;> <;>, 4 juv. from Villefranche, off the " Plage des Marinieres " coarse sand under vegetation of Posidonia. Depth 3 m. Above T have asked attention for the fact, that according to me A. acuminata and A. pellucida are distinct species (confer p. 29). Female and male presented the following dimensions cf : 1,56 mm; a. = 32,5; ~ = 3,23; y = 7,1. Frr..IPJEv's formula : fl- <;> : 2,1 tnm; r.j. = 34,3; ~ = 4,1; y = 7,3; v. = 53,3%-

31 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 33 FILIPJEv's formula : !L Dimensions of EBERTH's : cf: 2 mm; <j>: 2,5 mm; (J. = 26; (]. = 25. ~ = 3. After the indications given by EBEll.TH it is not certain that in both male and female the oesophagus measured 1/3 of the total length of the body. There exists however a striking identity in the relative oeso'phageal length between my male and that of EBERTH, which brings I think the justification of EBERTrr's observations and meaf3urements and is in contradiction with the postulation of CoBB (1891) where this author says : «seemingly by a misprint the neck was stated to be one-third as long as the body». A further difference between A. acuminata and A. pellucida is the situation of the excretory pore. The excretory pore is found at a level with the cervical hairs and far behind the amphids separated by a distance, slightly less than 1/ 4 of the whole oesophageal length from the anterior end of the body. The opening of the amphids is situated at 1/4 from the distance between the anterior border of the head and the foremost of the row of 4 cervical setae. Width of amphidial opening 28 % of the corresponding body diameter, and as far from the anterior head border. Foreborder of the head bluntly rounded. Buccal cavity narrow. 10 cephalic setae. The submedian setae are paired and unequal in size; the longer setae equal 71 % the corresponding body diameter. Nervering at 48 % of the oesophageal length.!spicula curved, with fine velum and short manubrium. Spicular chord almost as long as the anal diameter. Gubernaculum short, of fine texture. Praeanal tube, 2 anal diameters in front of the cloaca. Male tail gradually tapering to a rather long and filiform flagellum, the latter slightly swollen at its tip. The tail bears some minute setae in scattered position. Length of male tail nearly equal to 8 anal diameters. The female tail is 10 anal diameters long. GEoGRAPHICAL DISTRIBUTION : Nice, Banyuls, Cette, Naples, Adria, Baleares, Mallorca, Ibiza. Genus STENOLAIMUS MARION, i860. The present material brings 2 species of the mentioned genus a long-tailed form Stenolaimus paralepturus n. sp. and a form with distinc~ly shorter tail Stenolaimus metagracilis n. sp.

32 34 J. H. SCHUURMANS STEKHOVEN JR Stenolaimus paralepturus n. p. (Fig. 6, A-F.) 1 9, from Villefranche, off the " Plage des Marinieres,, coarse sand under vegetation of Posidonia. Depth 3 m. 1 cf, 1 9, 2 juv. from Villefranche, between the " Lazareth, and << Anse Passable», grey mud. Depth 50 m , 2 juv. off the" Pointe de la Gavinette,, grey mud. Depth 80 m. FrLIPJEV h as given in 1928 a good figure of the male Stenolaimus gracilis (von Lr stow). SouTHER (1914) did depict both male and female of tenolaimus marioni (SouTHER ') after specimen from the lri h ea. In 1931 ScHuuR rans STEKHOVE' and AnA r found a juvenil pecimen of the latt r species in material from the Belgian Goa t. R centl (1932) LLGEt ha o-i en a compilation of the litterature on the Genus Stenolaimus, LLGE come to the conclusion that the my teriou type pecie t. lepturus, colle ted n ar Marseille, should be kept in the genus Stenolainws. After having described three new pecie of Stenolairnus, I intend to om<' back on the interrelations between Stenolaimus and the Phanodermatidce. Dimensions : cf: 5,64 mm; a. = 40,2; ~ = 3,06; M y = P. 9 1: 4,82 mm; 9 2: 5,8 mm; (1. = 34,4; ~ = 2,6; y = 12,76; 4820 p.. a. = 41,4; ~ = 3,6; y = 11,6; fl. v. = 64,3 %. v. = 64,1 %. The species of Stenolaimus undoubtedly are the mo t difficult lo identif because the differences between the species are incon picuou and e peciall. because the head portion misses outstanding characleri tic feature. The present species is most closely allied to St. gracilis (Lr TO~ ), differ from it i.a. in its size, which might be partly due to the fact that repre entant of a certain species collected in southern latitudes are generally mall r than those of northern latitudes. Moreover in my specimen the excr lor pore i placed somewhat more forward. Apparently however St. gracilis mi e the cervical setae, that are placed here more or less in rows. Similarly there i a difference in shape and size of the amphids between my pecies and gracilis. Neither are there in gracilis praecloacal setae, whereas also the hape of the gubernaculum is quite different. A comparison with St. marioni So THER makes it clear that it gubernaculum differs with that of the mentioned species. Further differences are found

33 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 35 in the pilosity at the anterior body end, and in the position of the excretory pore. St. lepturus MARION at its turn is much smaller and besides possesses cervical hairs placed in dense longitudinal rows. It possesses an excretory pore which is placed much more forward than in the present species and finally it possesses a tail which is distinctly more slender than in our species. So I feel obliged to create a new species for the specimens of Villefranche, for which I propose the name paralepturus. Body trongly attenuated anteriorly, its width at the anterior end is hardly more than 16 % of the width at the posterior end of the oesophagus. Cuticle smooth, provided with longitudinal rows of widely spaced cervical setae at the lateral sides, whereas the male po sesses some prae- and postcloacal medioventral setae. Amphids pouch-shaped, situated immediately behind the cephalic suture, amphidial slit transverse, 29 % of the corresponding cephalic diameter. Head with prominent, more or less fleshy lips, provided with prominent labial papillae, a narrow buccal slit, but no true buccal cavity, since the oesophagu is attached to the foreborder of the buccal funnel. 10 cephalic setae, of ' hich the submedian ones are paired; the partners of each pair slightly unequal in size, the longer ones measure 58 % of the corresponding cephalic diameter. In one of the females a distinct «rinnenformige Grube» was ob erved. Excretory pore situated at 5 cephalic diameter from the anterior end of the body. Spicule very long, their length equalling 7 anal diameters, slightly swollen at their proximal end, filiform, presenting an attenuation towards.the distal end, after which they widen again and are pointed at the extreme apex. Gubernaculum of complex structure, showing proximal excresences of coar~e texture; middle portion thickened. Length of gubernaculum equal to 1,4 anal diameters. Tail in both sexes long, conical at its base, quickly tapering in its ba al third, apical 2/ 3 filiform, extreme apex pointed. The male tail shows, like mentioned above, a scar e pilosity, whereas the female tail is almost devoid of hairs Stenolaimus metagracilis n. sp. (Fig. 7, A-D.) 4 <? <?, from Villefranche, off the " Pointe de la Gavinette n, grey mud. Depth 80 m. Dimensions : <? 1 : 6,26 mm; a. = 52; ~ = 8,23; y = 14,2; v. = 53,3 % so 6260 p.. <? 2: 6,7 mm; a. = 67; ~ = 8,3; y = 13,4; V.= 53,7 % p..

34 36.T. H. SCHUUR IA l TEl HOVE l Jn. The main difference bet"\ en thi and th for o oin o lie in th horter 1elative length of the o ophao-u, the mall r number eta ompoing the row of cervical setae in the di lin tly h rt r flagellum of the tail, and the more forward po ilion of the ulva. A D 7 c A B c 9 8 A FIG Stenolaimus metagracilis n. sp. A C : Female head end. B D : Female tails. FIG Halalaimus gracilis DE MAN. A : Female head end. B : Base of resophagus. C : Female tail. FIG.. - tenolaimus breuicauclatus n. p. A : Female head. B : ame head enlarged. C:: Tail. FIG Tre{u ia longispiculosa BRESSLAU and CHUURl\lANS STEKHOVE.'i. A : Male head. B : Male tail Head distinctly set off against the remainder of the body, with promin nt labial papillae. Cephalic setae comparatively long, subequal a far a the are found in pairs, measuring 71 % of the cephalic diameter. Vulva di Linctl more forward. Neither amphids nor excretory pore obser ed. Tail conical at base, rather quickly tapering to the comparatively short flagellum, which occupies 47,5-57% of the whole tail length. Length of tail equal to 5,6-6,6 anal diameter. On the tail some few scattered setae.

35 FREELIVI 1 G MARl TE EMAS OF THE MEDITERRA 1 EAN Stenolaimus brevicaudatus n. sp. (Fig. 8, A-C.) 1 ~. from Villefranche, off the " Plage des Marinieres,, coarse sand under vegetation of Posidonia. Depth 3 m. The female in question shows great affinities to St. paralepturus. At the same time one is inclined to think at a representant of the genus Klugea, but this is difficult to decide after a female only, since the main difference between Stenolaimus and Klugea lies in the presence or absence of a praecloacal tubulus in the mah sex. The present female differs from St. lepturus MARION in the comparatively shorter tail and especially in the shorter length of its flagellum. Like in other species of Stenolaimus vve find a «rinnenformige Grube». Dimensions : ~ : 6,68 mm; a. = 25; ~ = 3,9; y = 15,7; v. = 61 % i p.. Head distinctly trilobed, each lip with 2 prominent labial papillae. Cephalic capsule absent. Cephalic suture sinuous, immediately followed by a crowu of 10 cephalic setae, those situated in the lateral fields particularly small and not surpas ing 20 % of the cephalic diameter, the longer parthers of the sub median pair measure 55 % of the corresponding diameter, the shorter partner& 44 % of that same diameter. Amphids just posterior to the sinuate suture line of the head, almost 15 % of the corresponding diameter. Tail conical at its basal 3/ 5, filiform at its apical 2/ 4 only. Excretory pore on 4,6 cephalic diameter from the anterior head end. Lateral fields 1/ 3 as wide as the corresponding diameter. Caudal glands contained in the interior of the tail only and not urpa ing thi limit. Some minute setae are scattered over the tail as well over the oesophageal portion of the body. A comparison of the present form with FrLIPJEv's Klugea trilabia brings about differences in the relative tail portions and in the data of the cephalic setae, ' hich are comparatively longer than in our species. Drsc 10 : The head of Stenolaimus resembles the head of Phanoderma, although it misses a true cephalic capsule. In details it has also many points in common with the head of Anticoma. At the other hand we have to bear in mind that neither Micoletzkya nor Phanodermopsis, according to ScHUURl\IANS 1STEKIIOVE (1935) both belonging to the Phanodermatidce possess a cephalic cuirass. The male genital armature of Micoletzkya is quite similar to that of Stenolaimus. In the latter genus however the praeanal tube, which Anticoma, a~ well a Micoletzkya and Phanoderma have, is lacking. It must be stated that Anticoma and Stenolaimus occupy a more or less isolated position in the

36 38 J. H. SCHUURMANS STEKHOVEN Jn. family of Leptosornatidce, whereas both have features in common with the Phanodermatidce. If we should hift Stenolaimus to the Phanodermatidce, the same thing ought to be done with Anticoma. The microscopical structure of both lastnamed genera is insufficiently known and so it would be premature to change at present the systematic position of A nticoma and Stenolaimus, although future researches at the hand of a large material may prove, that it will be necessary to regroup several Leptosomatidce and Phanodermatidce. For the present we will however leave Stenolaimus in the Leptosorn.atidce family. Genus HALALAIMUS DE MAN, Halalaimus gracilis DE MAN, (Fig. 9, A-C.) 1 <j> in rather bad condition from Villefranche " Baie de Lilong», sand. Depth 5 m. 1 <j>, Villefranche, off the " Porte de la Gavinette,, grey mud. Depth 80 m. The tip of the tail of the female of Baie de Lilong in question ha b en snapped. In its dimensions and in the distribution and relative ize of th cephalic setae it fits quite into the scheme of the mentioned pecie. Foreborder of amphids 7 cephalic diameters from the anterior headend. The amphid themselves are however comparatively longer than for in tance in the pecimen depicted by DE MAN. In DE MAN's specimens the amphidial slit were 1,5 time as long as the distance from the anterior border of the body to the amphid. In the female from Baie de Lilong this relation i 10,8 : 1, which r lation however may fall in the range of variations a species pre ents. Dimensions of the other : <j> : 1,48 mm; ~ = 3,5; '{ = 5,45; v. =55% '- In dimensions this female falls quite in the range of variation of Halalaimus gracilis, like also the figure may show. GEoGRAPmCAL DISTRIBUTION : North Sea, Baltic, <Jresund, Trondjhem fjord, Stappen, Coast of Norway, Mediterranean, Sea of Marmara, Suez.

37 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 39 Genus TREFUSIA DE MAN, Trefusia longispiculosa BRESSLAu & ScHuuRMANs STEKHOVEN, 1935 (Fig. 10, A, B.) 1 cf, 1 ~, from Villefranche, between the " Lazareth, and " Anse Passable n, grey mud. Depth 50 m. Dimensions : ~ : 2,4 mm; a. = 67; 0 16 ~ = 9,15; y = 2,26; v. = 31,6 % p.. The specimens were in rather bad condition, but so far as might be concluded from the available data, they belong to the species created by BRESLAU and ScHUURMANS STEKHOVEN. The head presents the typical Trefusia type with the more or less fleshy lips, crowned with minute labial papillae. There are 6 digitate cephalic setae, each measuring 40 % of the corresponding cephalic diameter. Somewhat more backwards a cervical crown of sim ilarly digitate setae is found. The length of these setae is 30,5 % of the corresponding body diameter. Buccal cavity minute, more or less caliciform. The oesophagus is attached at the anterior border of the head. Oesophagus cylindrical. Nerve ring at 59 % of the oesophageal length. Tail very long and twisted with a long flagellum which ends blunt, with a rounded tip. Flagellum occupying 43,5 % of the tail length. Length of tail equal to 22,2 anal diameters. DiscussiO : CoBB (1893) has found at Naples a species which he called Rhabdocoma macrurum CoBB. This species resembles our form. It has a imilar h ead, similar position of cervical setae, but differs from Trefusia longispiculosa in the shape and size of the spicula. The spicula of Tr. longicauda however are similar in shape to those in both species of Rhabdocoma. The shape of the tail of both Trefusia and Rhabdocoma is again identical. Unfortunate! I have not observed the amphids of the specimens of Villefranche. Those of Trefusia are cyathiform with a cryptospiral slit, whereas the amphids of Rhabdocoma are quite circular like in the Monhysteroidea. Till we know more about it I have left Rhabdocoma under the Monhysteroidea. The dim en ions of Rh. macrurum do not differ much from those of Tr. longispiculosa, neither do the indices. Further material is urgently wanted to study the affinities of the mentioned species. GEOGRAPHICAL DISTRIBUTION Helgoland, Mediterranean.

38 40 J. H. SCHUURMANS STEKHOVEN Jn. FAMILY PHANODER.MATID~. Genus PHANODERMA BASTIAN, The genus Phanodenna comprises a number of species, most of which are comparatively insufficiently known. In 1924 MrcoLETZKY has given a synoptic key for the mediterranean species, based on the males of the species, he had studied from that region. Unfortunately extensive descriptions of the new species the said author did create at that occasion never were published so that we are confined to the scanty data given by lviicolet'zky. This is very regrettable because the Mediterranean proves to be ri h in species belonging to the mentioned genus. Mo t species of Phanoderma e m to be comparatively rare. Seldom more than a couple of specimen of uch a species is found, which forms a hindrance to a thourough tudy. In a footnote MICOLETZKY utters his doubt if the specimen from Teneriffa which TEI ER (1921) did identify with Ph. tuberculatum (EBERTn) really belona to that species, beca11sp. MrcoLETZKY says : «no males wer available». cording tu lviicoletzky new studies are urgently wanted to state if ' e are able to di c rn the different species of Phanoderma after the female. The material I have to my disposition from Villefranche a well a fr m Alexandria brings me to the conviction that the female too rna rvc Lo distinguish between the species of Phanoderma. Not only the shape of lh tail, but also the relative position of eyespot and e crctory pore, a w II a ~ the pilosity of head and body doe enable us to identify a certain femal. Moreover I was fortunate enough to find the mal partner to th TET 'ER ' species of Teneriffa. Now it became evident that TEI En's Ph. tuber ulatum in reality belongs to a distinct specie, which like a urvc of the literatur taught me, is identical with the pecies de cribed by DtTLEV E ' a Phanoderma cocksi BASTIAN and later on brought to Phanodenna ditlevseni FILIPJEY b FILIPJEV (1925) Phanoderma ditlevseni FILIPJEV, (Fig. 11, A, B.) 2 d' d', 1 ', from Villefranche, off the " Plage des Marinieres,, coarse sand under vegetation of Posidonia. Depth 3 m. Dimensions : d' 1 : 3,780 mm; FILIPJEv's formula : a. = 36,7; ~ = 3,7; y = 33, M p.. d' 2 : 3,880 mm; a.= 38,8; ~ = 3,6; y = 23,3. FILIPJEV's formula : M p..

39 FREELIVI TG MARINE NEMAS OF THE MEDITERRA EA 41 <j> : Length 3,144 mm; ;;, = 41,3; ~ = 3,13; y = 28,07; v. = 64,6 % - FrLIPJEv's formula : p.. Head strongly attenuated anteriorly, truncate at its apex. Labial region crowned with 6 labial papillae. Cephalic capsule with long and slender posterior excrescences, that surpass the cephalic suture in caudal direction, over a little distance. Cephalic setae comparatively long and slender, 10 in number, the ubmedian ones paired, subequal, the longer partners measuring 43 % of the corre paneling cephalic diameter, whereas the shorter partners and the lateral unpaired setae do not surpass 39 % of the corresponding diameter in length. Lateral setae slightly more forward than the submedian pairs. Amphid immediately posterior to the lateral setae, their openings comparatively large, e pecially in comparison with those of Ph. tuberculatum (EBERTH), 20 % of the corresponding body diameter. Eyes distinct, pigmentspots square. The anterior end of the pigmentspot is separated from the anterior hean end hy a distance equal to 1,57 times the cephalic diameter measured at a level with the setae. The excretory pore is separated from the head end by a distance equal to 2,07 time the di tance head end-eye-spots. In the female from Teneriffa, studied by tstei ER, this distance was 2,15 times the distance head end to eyespots. The number of setae is identical to that found in Ph. tuberculatum EBERTH a can be tated after EBERTH's figure, but Ph. tuberculatum EBERTH easily may be distino'ui hed from the present species by the much longer setae in the oe ophageal region. In the present species these setae are short and irregularly cattered, not arranged in rows, like was depicted in EBERTH's figure. Buccal cavity bordered by 3 cuticularized plates of unequal strength en length. Oe ophagus cylindrical. Nerve ring at about 34 % of the oesophageal length, that is lightly anterior in comparison with the specimens studied by EBERTII. In the female of Teneriffa the nerve ring was situated at 37,9 % of Lhe oesophageal length. At fir t ight the male O'enital armature of my specimens resembles that of the type species. But closer comparison reveals several essential differences. In it general shape the spicula are similar to those of the type species, but if we consult MrcoLETZKY's synaptical key we are aware of the fact that the picula in Ph. tuberculatum are not barbed or provided with a denticular ridge like this is the case in the present species and further that Ph. tubercuculatum has a very inconspicuous gubernaculum, whereas the same structure is very prominent in the present species. These differences alone I think would suffice to separate the present species from Ph. tuberculatum EBERTH. The praeanal tubulus, separated from the cloacal aperture by a distance equal to 2,5 anal diameters in found in front of

40 42 J. H. SCHUURMANS STEKHOVEN JR A A c 12 B FIG Phanoderma ditlevseni FILIPJEV. A : Male head. B : Male tail. FIG. 13. Phanoderma laticoue (MARION). A : Head juvenile specimen. B : Tail of the same. FIG Phanoderma nasulum n. sp. A : Female head. B : Female tail. C : Female tail, greatly enlarged. FIG Phanoderma parasiticum DITLEV EN. A Female head. B : Female tail. the proximal end of the spicula. Spicula slightly curved, provided with a single barb near the distal end, where one finds similarly a denticular ridge. Distal end of spicula with a blunt point, proximal end of the same slightly swollen but not bulbar. Length of spicula equal to 2,5 anal diameters. Gubernaculum in the shape of a fine sheath. The praeanal tubulus and the

41 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 43 cloacal aperture are connected by means of 2 rows of subventral minute bristles, each row composed of 7-8 setae cuticular bands compose the bursal musculature. Cell bodies of spinneret glands shifted to the praecaudal part of the body but not further anterior than the proximal end of the spicula. Cell bodies twisted. Tail elongate conical, 2,25 times as long as the anal diameter, provided with a terminal spinneret. Along the tail some short scattered setae. Female resembling the male in most particulars. Amphids of the same relative diameter. Nerve ring at 25,5 % of the oesophageal length. Body of excretory eel, ending in front of the posterior end of the oesophagus. Tail like in the male, elongate conical, gradually tapering towards the apex, 2,7 anal diameters long. In Ph. tuberculatum EBERTH the tail has a somewhat different shape. Here the tail possesses a more knobbed end and bears longer setae too. The present specimens ~re almost quite in accordance with the description g iven by DITLEVSEN (1923) for his Phanoderma cocksi BASTIAN from the river Auray and from Glenans (Cotes de Bretagne et Rockall). In all essential features our specimens agree with those from the said species. Apparently the tail of DITLEVSEN's male of Ph. cocksi was comparatively shorter than that of my male but even more so than that of DITLEVSEN's female, which shows a tail of similar hape as that of the male in question. DITLEVSEN's male had a tail which measured 1,6 anal diameters, whereas the female partner had a tail of which is quite 2 anal diameters long. At the other hand the relative position of the eye pots and the excretory pore is such that the latter has been shifted nearer to the eyespots than was the case in my specimen from Villefranche. In the female studied by DITLEVSEN the excretory pore was separated from the anterior head end by a distance equal to 1,64 times the distance anterior head end-eyespots. The latter are situated on a distance equal to 1,4 cephalic diameters from the anterior head end which is almost quite as far as in my male. So I am convinced that not only my male but also STEINER's Ph. tuberculaturn from Teneriffa are identical with th,e species DrTLEVSEN did redescribe as Ph. cocksi BASTIAN. The species is closely related to Phanoderma gracile DE IA, but has a distinctly shorter tail. GEOGRAPHICAL DISTRIBUTION : Auray, Glenans, Villefranche, Teneriffa.

42 44 J. H. SCHUURMANS STEKHOVEN JR Phanoderma nasutum n. sp. (Fig. 12, A-C.) i C(, from Villefranche, off the " Plage des Marinieres " coarse sand under vegetation of Posidonia. Depth 3m. At first I was inclined to reckon this female, since it was found in the same sample as both males of the foregoing species to Phanoderma ditlevseni FILIPJEV, but closer observation learned me that such an identification was impossible, since 1) the anterior head end is even more sharply attenuated than in that species, 2) because the excretory pore, which is very incon picuou, opens quite near the eyes and 3) because the three caudal cell glands arc shifted far forward and are not twisted like in Ph. ditlevseni FILIPJEV but occup a tandem position. The foremost glandcell is much more forward than in STEINER's male from Ph. ditlevseni from Teneriffa. The female in question makes a much more slender impression, although it is in a state of high pregnancy, than the males of the former specie. Dimensions : Cj!: 3,i44 mm; (1. = 4i,3; ~ = 3,i3; r = 28,07; v. = 64,6 % ii4 fj. Head end pointed, rounded anteriorly. Labial papillae in on picuou Head capsule weak, not very pronounced, not prolonged backward from the cephalic setae. The cephalic setae rather fine and lender, the submedian elae paired and half as long as the corresponding cephalic diameter, the lat ral setae slightly more forward and somewhat shorter i.e_ 40,9 % of the corre panding diameter. Amphids elongate, egg-shaped with a minute lit, not quite 14 % of the corresponding diameter. Some slender setae in the cervical portion of the head, placed more or less in longitudinal rows. Eye pots with o al pigmentspot, separated from the head end by a di Lance equal to l\ ice the cephalic diameter at the level of the cephalic setae. Excretory pore minute at a level with the eyespots. Buccal cavity narrow, embraced by three cuticular plates. Oesophagus narrow in the cervical region, then very broad and almost quite filling up the whole lumen of the body, its borders crenulated. Uterus with 4 well developed eggs. Caudal glands in tandem position, the foremost one more than 11 anal diameters in front of the anal aperture. Tail elongate conical, with a terminal spinneret. The tail is 3 anal diameters long. There is only a single praeapical seta on the tail. The head end of Ph. nasutum is very much slike that of Ph. laticolle (MARION). Both species may however be easily distinguished by their tails, which is elongate conical in nasutum, whereas the tail of laticolle possesses a filiform tip.

43 FREELIVI TG MARl E NE IA._ OF THE MEDITERR IE K Phanoderma laticolle (MAR TO, 1870). (Fig. 13, A, B.) 1 juv. from Villefranche, off the,, Plage des Marinieres, coarse sand under vegetation of Po idonia. Depth 3 m. ' Dimensions : 1 juv. 1,96 mm; rj. = 32,5; ~ = 3,26; y = 12, fl If one lool afte1 the figure iamo has given from his male, it becomes at once clear that the tail i everal limes longer than it anal diameter. 1 ow MARIO mention in hi li t of dimen ion, that the tail i 130 p. long and 80 p. ' ide at the anal aperture. If we uppo e that the last date i correct than the tail i in reality 337,6 p. long after the figure MARIO has given from his male. [n consequence the index i not 42,3 like we should think after the dimensions, onl 16,3. If Lhi i taken into account then our dimen ions are in good accordance with tho e of MARIO. The general hape of the tail in both cases a well a the circum Lance that the excretory pore opens quite near the eyepol bring me Lo the con iclion that my pecimen i con pecific \ ith MARION' Ph. laticolle. Head rounded anteriorly, not di tinctly set off against the neck, ince the anterior allenuation is le s distinct than in allied species. Cephalic cap ul di tinct, compo ed of cuticular plate, which extend rather far back \Yard. The plate that enclo e the buccal cap ule are fenestrate, when observed from the lateral ide of the body. Cephalic elae horter and distinctly more rigid than in the foregoing,pecie, 10 in number. Lateral etae slightly in front of the submedian pairs, immedialel follo" ed b the comparative! minute amphidial opening. Lenoth of lateral elae equal to 37,5 % of the corre pending cephalic diameter, the ubmedian elae although lightl longer than the lateral one measure onl 37 % of the corre pending diameter, because they are placed somewhat more back\ ard. Amphid mall, amphidial opening 16,6 % of the corre pendin a bod diameter. E e pol on a level ' ith the excretory pore, eparated from the anterior head border b a di lance equal to 1,84 cephalic diameter at the level of the implantation of the ubmedian setae. Pigment pots of eye roundi h. erve rino- al 50 % of the oe ophageal length. Tail 4,6 anal diameters long, rather lend r o-rad uall tapering, more or le with a flagelliform posterior portion. pinneret di tinctl. demarcated. Caudal glands ending ju t in front of the anal opening twi ted. Tip of tail lightly clavate. GEoGRAPHICAL m TRIB TIO ' : Marseille (MARION), Villefranche, Alexandria.

44 46 J. H. SCHUURMANS STEKHOVEN JR Phanoderma parasiticum DITLEVSEN, (Fig. 14, A, B.) 1 <j?, from Villefranche, between the " Lazareth " and " Anse Passable ", grey mud. Depth 50 m. Dimensions : 5,34 mm; a. = 39,5; ~ = 5,93; "( = 24,2; v. = 50,5 %. FILIPJEv's formula : fl. DITLEVSEN'S female : Length : 6,2 mm; a.= 41; ~ = 5,2; "( = 20,5; v. =59%. Although my specimen present some slight differences with the type specimen discovered by DITLEVSEN (1926) near Hanstholm I feel justified to bring the specimen in question to that species. At the same time I must point to an error in the numbering of the figures on page Vb 24 of my book on the Nematoda errantia in : Die Tierwelt der Nord- und Ostsee, where what i indicated as figure 96 b, is in reality figure 95 b, whereas the figures 95 b and 95 c should bear the numbers figure 96 b and 96 c. This species is characterized by the fact that it misses the ocelli and ha a tail, which conical at its proximal portion suddenly attenuates and pre ent a rather long filiform tip. Head truncate, almost parallel-sided. Labial papillae prominent. Cephalic setae 10 in number, distributed as usually, 75 % of the corresponding cephalic diameter. Amphids not seen. Buccal cavity rather wide, its wall strengthened by strong cuticularisations, that are the folds of the cephalie capsule, the walls of which near each other so close, that there remains onl a very minute slit between both lamina of each fold. Excretory pore at a distance equal to 3 cephalic diameters from the anterior end. Tail a described above, the filiform tip being somewhat longer than in the specimen of DITLEVSEN, length of tail 2,6 anal diameters, that of the filiform portion ju t as long as the anal diameter. The conical portion of the tail bears some rather long, irregularly scattered setae. GEOGRAPHICAL DISTRIBUTION : Danmark (Hanstholm), Villefranche Phanoderma elegans n. sp. (Fig. 15, A, B.) 1 <j?, from Villefranche, " Baie de Lilong "' sand. Depth 5 m. This species is characterized by its slenderness, by its rather weak head capsule and the elongate filiform tail, which is even much more slender than in DE MAN's gracile. Dimensions : <j? : 3,104 mm; a.= 51,7; ~ = 4; "( = 13,3; v. = 44,2 % fl

45 FREELIVING MARINE EMAS OF THE MEDITERRA EAN 47 A 15 B A 16 B A 17 FIG Phanoaerma elegans n. sp. A : Juvenile head. B : Tail. Frr Gal eonema l ongicau da n. sp. A : Juvenile h ead. B : Tail. FIG Enoplu mer idionalis STETNER. A : Ma le h ead. B : Tail. FIG Mesacanthion tricuspis n. sp. A : Male head. B : Male genital armature. C: Spicula and gubernaculum. D: Juvenile head. E : Tail of the same. F : Head of the other juvenile. G : Tail of the same. Head truncate anteriorly. Labial papillae not very conspicuous. Head cap ule not vigorous. Cephalic setae rather slender, the lateral setae 66 % of the corre ponding diameter. Amphids cyathiform, 22 % of the corresponding diameter. Eyespots separated from the head by a distance equal to 2,1 cephalic diameters. Tail elongate, more or less filiform, gradually tapering, length of tail equal to 4, 7 anal diameters. 4

46 .f. H. SCHUURMANS STEKHOVEN JR. Genus GALEONEMA FILIPJEV, Galeonema longicauda n. sp. (Fig. 16, A, B. ) 1 juv. from Villefranche, '' Baie de Lilong " sand. DepLh 3 m. Dimensions : Length: 2,86 mm; FILIPJEV's formula : ~ = 59,5; ~ = 3,08; y = 14, fl- This species, which is recorded here a new hows great affiniti to FtLIP JEv's Galeonema caudata. From the latter species it may howev r be distinguished at once by the much longer cephalic etae, the di tinctly et off h ad and by the fact that the tail is not effilate but more gradually tap r lo th rather narrow rounded apex. Head portion di tincll set off again t Ill remainder of the body, more or le s c lindrical, ' ith prominent lip and prominent labial papillae. Cephalic setae long, equal in length to the corr - ponding cephalic diameter, lateral setae slightly in front of the ubmediau pairs, immediately followed by the amphids, ' hich how a rather long amphidial pouch and a narrow amphidial slit, that measures 20 % of the corre ponding cephalic diameter. Cephalic capsule reduced; like in all other pe ie of the genus, we observe 3 pointed plates only round the buccal cavity. Oc IIi ab ent. Some short setae are observed along the oesophageal portion of the bod, placed more or less in rows. Excretory pore eparated from the anterior border of the head by a distance equal to 4,5 cephalic diameters mea ured at the le cl of the cephalic setae. Nerve ring at 41 % of the oesophageal length. Tail 6 anal diameters long and slender, graduall tapering to the more c linclrical portion, which is slightly swollen at its extreme apex. Caudal glands re lricled to the interior of the tail. The species shows some affinities as to its head with Chcetonema but undoubledly must be reckoned to the Phanodermatidae. For further data about its systematic position we have to wait for the detection of the respective male.

47 FREELIVJ G MARl JE E 1AS OF THE MEDITERRANEAN 49 FAMILY ENOPLID.lE. Genus ENOPLUS DUJARDIN, Enoplu. meridionalis TET ER, (Fig. 17, A, B.) 2 cf cf, 3 <? <?, 1 juv. from Villefranche, off the " Plage des Marinieres,, coarse sand under vegetation of Po idonia. Depth 3 m. 1 cj, 1 <?, from Villefranche, off the Station, same kind of habitat. Depth 15 m. The p cies in question answer be t to STEINER's description of Enoplus communis var. meridionalis, ' hich DE Co 1 CK and I (1933) have synonymized in 1933 with E. striatus EBERTII, nob ilh tanding the existing difference. Unf rtunatl 'TEI 'ER ha gi en meither a description nor figures of the anterior nd of hi pecimen. If however the male tail of both species are compared the all nlive ol> er er will find everal difference. Not only i the supplementar oro-an eparaled from the anal aperture by a greater di tance in striatus, like thi i illu lraled by EBERTH (1 63), than in STEI 'En's meridionalis, but be ide it hap i more tubular in meridionalis, more trumpet-shaped in striatus. l the other hand EBERTH depicts subventral rows of rather long praeanal etae in hi striatus, wherea the etae situated on the praeanal portion of the bod between upplementary organ and cloaca are more irregularly ~ cattered in meridionalis. It ha to be a ked in how far one must attribute pecific importance to the e difference, in how far they may be due to ubje live ob enation of the different authors. t the moment DE CoNI ' CK and I (1933) compared the literature, we had not yet specimen from the Mediterranean to our di po ition. Now that I have some of these I find another difference of importance, i.e. the relative length of the jaws, that are distinctly lana r in E. striatus EBERTH than in the pre ent pecimens as well as in tho e of E. comrnunis var. meridionalis. Thi brings me to the conviction, that L TEI ER E. communis var. meridional is which i neither a variety nor a ~ynon m of striatus, but a valid pecie ha to be named E. meridionalis. Dimensions : cf : 2,672 mm :X= 29; ~ = 5; y =12, f fl uticle mo th, ith minute setae irregularly di tributed e pecially over the o ophaaeal portion of the body. Head rounded anteriorly, not set off aaain l the remainder of the bod by a pecial con triction. Lip with 6 labial papillae. Cephalic. etae 10 in number, the partner of the ubmedian groups almo t equal in ~ ize (not equal in communis) 46,6 % of the corresponding cephalic diameter lateral etae unpaired, 35,7 % of the cephalic diameter.

48 50 J. H. SCHUURMANS STEKHOVEN JR. Amphids pouch shaped, their slit 11 % of the corresponding body diameter. Jaws three in number, with distinct median teeth; length of jaws 40 % of cephalic diameter measured at the level of the cephalic setae, blunt posteriorly, broadest in the middle, but only slightly attenuated towards the proximal end. In striatus the j aws measure 66 % of the corresponding cephalic diameter. Ja, s attached to the body walls by means of a cuticularized ring. No true ocelli, only pigment spots distributed in the oesophageal ti sue; the large ocalled ocellar spot is immediately followed by a couple of large setae; the other setae of the same region are however minute. Male genital armature con i ting of curved spicula, their cords being 1,5 times as long as the anal diameter; proximal end of the spicules attenuated, ventral surface with transver e indentations or incisions. Apex pointed. Gubernaculum short, embracino- the proximal end of the spicules, in the shape of an irregular ring with orne excrescences. Supplementary organ tubular, immediately in front of the proximal end of the spicula. Some hort irreo-ularly scattered etae in th pa between the cloaca and the supplementary organ. Tail conical, o-raduall tapering, the last third more or less cylindrical. Length of tail 3 time a long as the anal diameter. Some irregularly scattered setae are found on the tail, especially on its subventral region. Apex lightly dilated, it ' idth 1/ 7 lh width of the anal diameter. Length of STEINER'S : c1 : 2,531 mm; a. = 26,1; ~ = 6,4; y = Probably MrcoLETZKY's specimen from Suez belongs al o to the species : ~ : 2,6 mm; 11. = 23,5; ~ = 6,1; y = 11. GEoGRAPHICAL DISTRIBUTIO : Teneriffa, Villefranche, Suez, lexandria. arne Genus MESACANTHION FILIPJEV, Mesacanthion tricuspis n. sp. (Fig. 18, A-G.) 1 cj, 2 juv. from Villefranche, off the «Pointe de la Gavinette " grey mud. Depth 80 m. 1 juv. from Villefranche, entrance of the road, grey mud. Depth 230m. The new species presents close affinities to Mesacanthion klugei FrLIPJEV. With this species it has in common that the spicula are compo ed of two portions of divergent structure, opposite to what we find in other specie of the same genus. M. klugei and M. tricuspis may however easily be distinguished by differences in their pilosity as well as by the structure of their spicula. In klugei the pilosity of the head end is distinctly more dense, moreover longer than in tricuspis. As for the structure of the spicula, the proximal portion of the spicula is in klugei narrower than its distal portion, whereas the reverse is

49 FREELIVING MARINE NEMAS OF THE 1EDITERRANEAN 5t true for tricuspis. The gubernaculum, although small-sized in both species i circular to heart-shaped in tricuspis and anvil-shaped in klugei. So it is ju tified to create a new species for this mediterranean form. Unfortunately the tip of the tail of my only male specimen was broken of. If one take into account that the taillength in pecie of thi type is hardly much longer in adult pecimen than it is in larval forms, then we may estimate its length on 150 p.. Length of a male : 2,862 mm; (l = 28,6; ~ = 3,7; y = 19. FILIPJEv's klugei: 2,03-2,35 mm; (l = (29); ~ = 3,5-4 (4,1) ; y = 17-18,5. Therefore in n-eneral dimensions FILIPJEv's klugei and tricuspis are almost id entical. FrLIPJEv's formula : Juveniles specimen 1 : Length: 1,636 mm; (l = 29,2; ~ = 3,49; y = 12,7, Specimen 2: Length : 2,040 mm; '1. = 34; ~ = 4; (Anlerlor end or spicules) ~ f-l y = 14,5, 2040 f-l 2862 f-l In all three cren ra : Enoplolaimus, Mesacanthion and Enoploides, juveniles differ from adult pecimen in that their cephalic pilo ity i much le s developed. uuch fit like' i e for our pecimen. Th tail both in the male and in the juvenile i conical in its ba al 2/ 3, po t rior third lindrical, lightl wollen at it extreme apex. The head end di tincll lap r i lono-er than wide. Head with three lips, each lip with an apical flap, the laller crooked. nterior crown of head en e organs composed of 6, tiform papillae. In j u enile there i a crown of apparently 10 cephalic. eta of minor ize, ' herea the adult male pre ent a posterior crown of 10 etae of comparative! lono- ize, the longer ones almo t a lono- a the corre, pondin o- ephali diameter and 71 % of the diameter at the suture. horter partner of the ubmedian pair mea ure only 53 % of the cephalic ulure. An intermediate crown of setae likewi e eems to be composed of 10 element. Buc al cap ule conical trenothened by the cuticularized walls. From the bollom of the avil 3 teeth ari e one of which, the dor al, lightly outreache both ubventral teeth. The la t two reach ju t to the level of the cuticular rim. There i a cephalic organ oppo ite to the upper border of the dor al jaw.

50 52 J. H. SCHUURMA S STEKHOVEN JR. Spicula 2, 5 anal diameters long, composed of two portions, distal portion narrow, thinwalled, proximal portion in the shape of a gutter, which is narrowly open above, proximal end of the latter distinctly widened. Distal end of the spicules pointed. Gubernaculum small adhering to the spicules at their distal end. Supplementary organ tubular, opposite to the articulation of both portions of the spicula, just like in klugei. In the juveniles there is only a single crown of minute setae just posterior to the fleshy flaps of the labia on the level of the cephalic organ. The other setae are lacking. Juvenile tail 2,8 times as long as the anal diameter, provided with some short setae along the dorsal surface and om setae near the tip. The difference our pecies sl1ows with FILlPJEv's klugei in re p ct ' ith its spicules partly depends on the angle, under which these are ob erved. Genus ENOPLOIDES SSAVELJEV, i9i Enoploides amphioxi FrLlPJEv, (Fig. 19, A-C.) i ~, from Villefranche, off the " Pointe de la Gavinette n, grey mud. Depth 80 m. A c 19 B FIG Enoptoides amphioxi FILIPJEV. A : Female head. B : Head, optical section. C : Female tail. FIG Oxyonchus duijius FILII'JEV. A Female head. B : Female tail. The female in question was i~1 rather bad condition, but could be identified after the structure and pilosity of ils head end as well a after it general shape and the shape of its tail. Dimensions : Length : 4,4 mm; FILIPJEv's formula : 'J. = 44; ~ = 3,86; y = 24,4; v. = 53,i % fj. GEoGRAPHICAL DISTRIBUTION Black ISea, Sebastopol, Cernov, Villefranche.

51 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 53 Genus OXYONCHUS FILIPJEV, Oxyonchus dubius FILIPJEv, (Fig. 20, A, B.) 1 ~, from Villefranche, " Baie de Lilong», sand. Depth 3 m. Length: 2,5 mm; FILIPrev's formula : FILIPJEv's female : Length : 3,375 mm; ~ = 39; ~ = 4,31; y = 9,6; v. =52% ,... 0 (L = 42; ~ = 4,5; y = 8; v. = 60%. Our pecimen an wers fairly well to FILIPJEv's description. In its bodyhap in the con iderable length of its tail especially, a well as in the distribution of the etae the present female shows a striking resemblance te FILIPJEv's 0. dubius. Bod attenuated almo t b ice anteriorly, le s so posteriorly. Cuticle de oid of etae except in the cephalic body region. Head end conical with three fleshy, comparatively low lips, each crowne(,] with 2 labial etae. The e are lightl longer than the lips are high and mea ur 55 % of the corre ponding cephalic diameter. There is a crown of at lea t 10 cephalic etae, the ubmedian one of which are paired. Submedian tae unequal, the lonaer partner equal 88 % of the corresponding cephalic diamel r lh horter one doe not urpa 41 % of that diameter. Subventral ja' r prominent reaching till in front of the cuticular rim. Tail elongated, lender graduall tapering towards the apex, 9 times as long as the anal diameter. In FILIPJEv' female the tail was 10 times a long as the anal diameter. GEoGR PlllCAL m TRIB TIO : Black ea, Sebastopol, Amphioxus-ground near the corgian Mona tery, 9 fathom, Villefranche. FA IlLY DORYLAil\UDlE. Genus DOLICHOLAIMUS DE MAN, Syn. Trissonchulus COBB, Clo e ob n a lion of the pre ent pecie' and a comparison of the literature hrin a me to the com iclion, that CoBB' Trissonchulus ha to be synonymized ' ith Doliclwlaimus. The pre ent specie i clo ely allied to Dolicholaimus obtusus BRE LA and en Rl\IA ' STEKHOVEN but differs frpm the latter in that it doe not po e the bod papillae which where ob erved in longitudinal rows on the anterior portion of the bod of that species.

52 54 J. H. SCHUURMANS STEKHOVEN JR Dolicbolaimus nudus ScnuuRMA s TEKrrovE, (Fig. 21, A, B.) 1 <j?, from Villefranche, " Baie de Lilong», sand. Depth 3 m. Dimensions : <j? : 5,7 mm;!x. = 52,7; ~ = 9,5; y = 285; v. = 42,1 %. FILIPJEv's formula : P. Cuticle totally devoid of setae. Head di tinctly set off again t the remainder of the body by a suture line. There are 6 prominent labial papilla, and apparently 6 groups of cephalic papillae, of which 3 are depicted in fio'ure 21. I am rather sure that the submedian papillae are in reality double, lik thi is the case in specimens of the same pecie, collected at Ale andria, but Lhi characteristic was apparently over een by me during th tud of the f mal' from Villefranche. Amphids wide and pouch- haped, adjacent to the utur line of the head. Arnphidial lit 33 % of the corre paneling bod, diameter. Buccal cavity embedded in the oe ophageal ti ue. Thi buccal cavil ontain 3 spears with biuncinate apex, like thi i the case in other pecie of th arne genus. These spears measure 14 % of the oe ophageal length. ringslightly in front of the middle of the oe opha()'u (47 %). Spinner t open in()' at the ventral side of the tail. Thi- mea ure onl 1,1 anal diam ter. The present female does not possess praeapical papillae on it tail. GEoGRAPHICAL DISTRIBUTION : Mediterranean, Villefranchc, Ale anclria. Genus ANONCHOLAIMUS n. gen Anoncholaimus rhopaluru 11. p. (Fig. 22, A-C.) 6 <j?, from Villefranche, off the " Pointe de la Gavinette,, grey mud. Deplh 0 m. The genus Anoncholaimus haws a for it 0' ncral oullook and e p iall as far as the oral cavity and the head end i con erned trace of r lalion hip with the Dorylaimidae, but from the known genera of that famil it i at one' distinguished by the broad oral cavity, which i quite devoid of teeth. On might also think at a representant of the genus Pelagonema CoBB an 1 if furlh r material would prove a close relation hip with that genu then Lhe O'Cil u in question would belong to the Oncholaimidae and in that ca e in the r lalionship of Pelagonema. With that family it has in common the circle of 6 labial papillae as well as the circle of 10 cephalic setae. Each of the lip i in the possession of a single labial papilla. Till we have to our di po ition the corresponding male sex the systematic po ition of the genu remain uncertain. And further I am not sure about the true nature of the amphids. There is a

53 FREELIVING MARINE NEMAS OF 1'HE MEDITERRANEAN 55 lateral cleft, immediately posterior to the lateral cephalic hair, which ressembles strongly an amphid, but more posteriorly opposite to the bottom of the buccal cavity one finds a circular figure, connected with a tube-like structure, which might also represent an amphid. If the latter would have the value of an amphid, like I am inclined to think it has, then the former would have the meaning of a cephalic organ like we find in some Enoplidae. Length : 1,076 mm; a. = 44,5; ~ = 10,7; y = 26,9; V. = 50,6 %. FILIPJEv's formula : f.l Head demarcated by a cephalic suture. 6 lips with as many conical papillae. Cephalic setae short, the components of the submedian pairs equally A 21 B A c 22 FIG. 21. Dolicholaimus nudus CHUURMANS SIEKHOVEN. A Female head. B : Female tail. FIG. 22. Anoncholaimus rhopa urus n. sp. A : Female head. B : Base of cesophagus. C : Female tail. long, mea uring 13,3 % of the corre ponding cephalic diameter. Head cleft Lran ver e at a level wilh the cephalic suture, its width equal to 54,2 % of the corre pondincr body diameter. Body tapering gradually to the anterior end, where il i 30 % a wide as at the posterior end of the oesophagus. Amphid ( P) circular lo oval, 39,8 % of the corresponding body diameter. Buc al ca il conico-c lindrical, with strongly cuticularised walls the trencrlh of which increase to the proximal end, being 3 times as long as its greate t width. Nervering at 65 % of the oesophagus length. Oesophagus without true bulbus, almost the same width throughout. Tail 4,2 times as long as the anal diameter, quickly tapering, conical at base, then filiform ending with a di tinct knob. The filiform portion of the tail with its terminal swelling occupie 65 % of the whole taillength.

54 56 J. H. SCHUURMANS STEKHOVEN JR.. FAMILY ONCHOLAJMID~. Genus ONCHOLAIMUS DUJARDIN, Oncholaimus dujardini DE MA, (Fig. 23, A-C.) This species eem to be one of the mo t common. pecies of the 1editerranean, as it frequently encountered by all authors who have made researche in this region. 1 juv. from Villefranche, " Baie de Lilong», sand. Depth 3 m. 3 <:f <:f, 3 <j? <j?, 4 juv. from Villefranche, off the " Plage des Mariniere», coarse sand under vegetation of Posidonia. Depth 3 m. Length of <:f : 1,960 mm; ct = 49; ~ = 5,1; y = 49. FILIPJEv's formula : U M p.. Length of <j? : 2,184 mm; a.= 45,G; ~ = 5,5; y = 27,3; v. = 66 %. FILIPJEV's formula : :-24:------H--48-: : p.. DE MAN's: <:f : 2,588 mm; a. = 50,7; ~ = 6,6; y = 66. MICOLETZKY'S : <:f : 2,53 et 3,06 mm; <:f : 1,83 mm, Adria. FILIPJEv's : C1. = 63,74; ~ = 7,8; y = 66,69, Suez. <j? : 2,85 mm; a. = 45; ~ = 7-8; y = MICOLETZKY'S : <j? : 3,44, 3,76 mm; a. = 57,68; ~ = 8,3-8,5; <j? : 2,2 mm; V. = 70 %, Adria. y = 50,63; V. = 77 %, uez. According to my opinion TEI ER' 0. dujardini from Dar-e - alam (1921) as well as from that Sumatra (1915) do not belong to the pre ent pecie. far as the specimens from Cette regard, who DE RouvlLLE (1904) ha' brought to this species we are not allowed to draw a certain conclusion after DE Ro - VILLE's description. Fortunately I have to my dispo ilion sorn copi of DE RouviLLE's drawings made by DE fa after the original clrawin<y of DE RouviLLE and consulting the e we may be rather ure, that at lea t lh females of the species DE RouviLLE considered to be 0. dujardini do belong to the same species, DE MAN has described as 0. dujardini. In respect "ith the males of DE RouvJLLE I am not so certain, because DE RouviLLE ha not depicted the circumcloacal setae. 0. dujardini is characterized i.a. by its rather broad buccal cavity, with one of its subventral teeth prominent and stout and reaching almost to the level of the cephalic setae. The cuticle presents along the oeso-

55 FREELIVJNG MARINE NEMAS OF THE MEDITERRA EAN 57 phageal region a comparatively great number of short and stout setae, more or less arranged in longitudinal rows. Excretory pore separated in one of my females by a distance quite equal to 2, 75 times the length of the buccal cavity. Tail in both sexes distinctly curved. 1Spicules sword-shaped. Cloacal region demarcated by a number of claw-like darns, not depicted on DE RouVILLE's figure. STEI 'ER's 0. dujardini of!sumatra (1915) may be separated from the pre en t species by the more slender buccal cavity, by differences in the shape of the ubventral teeth, by differences in the cephalic setae, by the more slender piculum which is swollen at ils proximal end as wen as by the presence of a gubernaculum, not seen by me in the species studied from the Mediterranean. o I think we must consider STEI ER's 0. dujardini as a separate species for which I propo e the name 0. steineri. Head with ui tinct lips, 6 labial papillae and 10 short cephalic setae. ubmedian setae paired, subequal, the longer ones not surpassing 14 % of the cephali diameter. Buccal cavity 2,25 times as long as its greatest width. Female tail curved ventrally, alma t 3 times as long as the anal diameter. 1ale tail likewi e 3 anal diameters long, its curvature embraces 90 degrees of the circumference of a circle. Spicules word- haped, 1,75 times as long as the anal diameter. Cloacal region demarcated by a number of darn-like short setae, the medioventral of which ha the arne shape as that in figure 4 c of DE MAN. Apart from these orne other etae are distributed over the dorsal surface of the male tail. GEoGRAPlliCAL m TRIB no : :Mediterranean, Toulon, Banyuls-sur-Mer, aple [DE fa (1865), MicOLETZKY (1924)], Ischia, Rovigno, Ombla Bay, Bocce di Callaro, Black Sea, Mallorca, lbiza, Alexandria, Occurs in Bandirma, Sea of farmara. ALLGE found it in Banyuls i.m. in great quantities. Genus ONCHOLAIMELLUS DE MAN, Oncholaimellus mediter-ra.neus ScrruuRMA s STEKnovEN (Fig. 24, A-D.) 1 (f, 1 ~, 2 juv. from Villefranche, farther end of the " Port de la Darse " black mud and organic detritus. Depth 3m. Dimensions : (f : 1,992 mm; :x = 41,5; ~ = 5,2; y = 27. FILIPJEV' formula : M 1920 _:. :...:.....:._... --:: Hl92 fj Dimen ion : ~ : 1,884 mm; ::J. = 33,6; ~ = 4,8; y = 17; v. = 42%. FILIPJEV's formula : i i884 fj-

56 58 J. H. SCHUURMANS STEKHOVEN Jn. As to their dimensions the specimens from Villefranche although they ressemble to 0. calvadosicus are not quite identical to the specimens formerly described by DE CoNINCK and me (1933) as such from the Belgian Coast. Moreover there exist some morphological differences, as well in respect with the male genital armature as with the cephalic etae, o that I feel obliged to bring them to a new species. In the male the setae distributed over the cuticle of the anterior portion of the body are particularly scarce and apparently horter than in th 0. calvadosicus male from Belgium. Cephalic setae 10 in number, in the female lh A B 23 c A 24 c D B I FIG Oncho!aimus dujaulini DE 1\lAN. A : Male head. B : 1\Iale tail. C : Female tail. I IG Oncho!aimel!us m editerruneu: 11. sp. A : Ma le h ead. B : Male tail. C : Female head. U : Female tail. shorter ones mea ure 34,4 %, the longer one 44,9 % of Lhe corre pondin<y bod diameter (in calvadosicus from Belgium the relative lenglh of lhe e ela wa respectively 41 and 51 % of the body diameter), in the male from ill franch the relative length o.f the cephalic setae was 61,5 and 50 % (th am being 100 and 81 %in the calvadosicus male from Belaium) of the corre paneling- cephali diameter. Buccal cavity 3,07 times a long a it greatest width. The larg subventral tooth, the length of which mea ure 84,8 % of the lenoth of th ~ buccal cavity, reaches till the level of the constriction of this cavil ; it is truncated distally. Dorsal tooth inconspicuous. Amphids small, ituated opposite to the posterior portion of the buccal cavity, cup-shaped, their lit in the male sex not wider than 1/7 of the corresponding body diameler. Nerve ring in the male sex at 47 %, in the female sex at 44% of the oesophageal length,

57 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 59 therefore more backwards than in calvadosicus, where it is found at % of the oesophageal length. Spicules in the male unequally long, the longest 4,3 the shorter almost 3 times as long as the anal diameter, proximal end knobbed, therefore slightly longer than in calvadosicus. Bursa copulatrix di tinctly developed, with darn-shaped papillae and some strong setae. Of the A A c G B F u 25 B I - l -:.:. ::. --:: ~ E ~111\llll ll'illff/fllj~ FIG. 25. FHip]evia meaiterranea n. sp. A : Juvenile head. B: Tail. FIG. 26. Metoncholaimus pristiurus (ZUR SrRASSEN). A : Female head end. B D F : Female tail. C : Male head. E : Demanian system. G : Male tail. latter there are 3 pairs, but I miss the median pairs, present in calvadosicus. Male tail 3,92 times as long as the anal diameter measured at the base, and just in front of the bursa, provided with a rather strong praeapical seta. Female tail 5 time as long as the anal diameter, cylindrical, swollen at its apex. GEoGRAPHICAL DISTRIBUTION : Mediterranean, Villefranche; Palma di Mallorca.

58 60.T. H. SCHUURMANS STEKHOVEN.Tn. Genus FILPJEVIA DITLEVSEN, Filipjevia mediterranea n. sp. (Fig. 25, A, B.) 1 juv. from Villefranche, between the " Lazareth " and " Anse Passable " grey mud. Depth 50 m. Dimensions : Length : 0,884 mm; FILIPJEv's formula : r:j. = 31,5; ~ = 5,6; y = 8, p KREis (1934) has postulated that in Filipjevia apparently neither lips nor papillae should be present. At the opposite the- present larva leads me to the conclusion, that although less distinct than in other species true lips as well a 6 labial papillae are present. Cephalic setae opposite to the distal end of th buccal cavity, just 1/6 as long as the corresponding cephalic diameter. Buccal cavity almost 3 times as long as it is wide. Amphids oppo ite to the ba e of the buccal cavity 1/3 as wide as the corresponding body diameter. Tail conical, gradually tapering to the apex, which is slightly swollen. Length of tail equal to 3, 7 anal diameters. Genus METONCHOLAIMUS FILIPJEV, l\jetoncholaimus pristiurus (Zun STRASSE, 1894). (Fig. 26, A-G.) 1 d', 1 <j?, 4 juv. from Villefranche, farther end of the " Port de la Darse " black mud and organic detritus. Depth 23 m. 1 d', 1 <j?, 3 juv. from off " Vieux Villefranche " black mud and organic detritus. Depth 20m. Dimensions : d' : 4,724 mm; 'J. = 69,9; ~ = 9,6; y = 27,4. FrLIPJEv's formula : M p.. <j? : 4,224 mm; r:j. = 58,6; ~ = 7,27; y = 19,2; v. = 65,3 %. FILIPJEV's formula : Specimens M. denticaudatus S. S. and ADAl\1 (1931). Dimensions : '-. d' : 5 mm; a. = 64; ~ = 8,33 (not 18,8 like stated in that description) y = 26,6. d' : 5,72 mm; a. = 63,8; ~ = 9; y = 25,6 (not 31,9 like stated by S-S and ADAM) V. = 69,39 % <j?: 6,9 mm; ':1. = 62,8; ~ = 9,9; y = 20,9; v. = 65,8 %

59 FREELTVI G MARl IE NEMA OF THE MEDITERRANEAN 61 In DE RouvJLLE' 0. albidus which is a synonym of M. pristiurus (ZuR 'TRA E ) the male mea ured 5,3 mm, which fall in the arne range of variation of the present species. Like easily may concluded from the foregoing not only the dimensions from lh pecimen from DE RouviLLE (1904) but al o those of S. S. and ADAl\l (1931) of DE MA (1878), as well as the pre ent pecimens fall into the range of variation of the species first described by Z R STRASSEN as 0. pristiurus ZuR TRA E. And imilar conclu ion are allowed in respect with CoBB's (1932) pecimen from the Atlantic Coast of Torth merica, where males and females likel attain a length from about 5,6 mm and for which CoBB did assume the nonymil with the pecimens from the 1editerranean. Tow I have been able to ob er e pecimcn from the Mediterranean, al o from imilar habitats as those tudied by DE Ro VILLE (Cette) and Z R 1 TRASSE ' (Naples) I am still more convin ed that the nonymizing from M. denticaudatus with pristiurus i ju lified b the fa l and I do not aaree with KREIS (1934), who i of the opinion that lh lru tur of the male tail a well a the amphid speak in favour of the eli tinctn of M. denticaudatus '. S. and ADAM. Therefore in order to bring new evidence that m la t conclusion was correct I rna gi e a rede cription of the female, illu lrated by new figures from this inlere ling pecie. Head rounded anteriorly with distinct lips, provided with minute lapial papillae. Cephalic etae at a level with the apex of the longer ubvenlral tooth, 10 in number, the longer ones 31 %, the shorter 26 % of the corre ponding diameter (in the Belgian specimens these measurements were 30 and 27 % of the corre ponding diameter re pectively). Amphids cup-shaped to mor cir ular, apparent! dependent on the tate of fixation, at a level with the horler buccal Leeth, which are connected with each other by means of a un ed cuticular rim. Longer subventral tooth % of the length of the bu cal ca it, horler teeth 64-74% of that di tance in the female sex. Between the ba e of the buccal ca ity and the excretory pore which is separated in the female ex b a di lance of 2,5 times the length of the buccal cavity from the anterior end (2,43 time in the Belgian pecimens) we find orne setae, apparentl placed more or les in longitudinal rm. Female tail 5,8 times a long a the anal diameter. The osmo~ium is situated halfways the intestinal efferent of the De l\ianian tern, i.e. in a imilar situation as depicted by CoBB (1932) for hi i\1. pristiurus (confer fig. 26 "ith CoBB's figure 1). The male tail wa not o trongl curved as in CoBB's male, but this certainly depends on the mode of fl ation, ince we rna ob erve also differences in thi respect between specimen of the arne habitat [confer Plate, fig. 7 and 8, S.. and ADAM (1931)]. The tail of our pecimen i provided with 8 awteethlike prominences and 7 etae, wherea the present pecimens pre ent, just like those from Belgium, the one tudied b DE Ro VILLE (1904) and tho e depicted by CoBB (1932) 4 praeanal setae of ' hich the foremost is separated from the other 3 by a larger

60 62 J. H. SCHUURMANS STEKHOVEN JR. distance than do separate the latter 3 from each other. Spicules 11 times as long as the anal diameter (just as in the Belgian males) (in Conn's males the spicules were 9 times as long as the anal diameter). Length of the male tail 5 anal diameters..similar relations were obse1;ved in specimens from Belgium. So I am sure that my former conclusions remain correct. GEoGRAPHICAL DISTRIB UTION : Helgoland, Belg ium, Mediterranean, Banyulssur-Mer, Villefranche, Cette, Naples, Atlantic Coast of the U.S.A. Woodshole. ALLGEN (1941) has found the species in question in Band irma, Sea of Marmara l\'letoncholaimus demani (ZuR STRASSEN, 1894). (Fig. 27, A-E.) 8 d' d', 4 ~ ~, 4i juv. from Villefranche, " Baie de Lilong,, sand. Depth 3 m. DE MAN (1878), ZuR STRASSEN (1894) as well as FILIPJEV ( ) have described this species, which is closely related to M. pristittrus (ZuR STR sse.) from which it may be distinguished easily in the female sex by the fact that the,. osmosium of the DEMANIAN system is placej. almost at the proximal end of the intestinal efferent duct, whereas it is situated in the middle of that eff rent in pristittrus. The male of M. dernani has a tail, provided with subvenlral setae, whereas pristittrus presents apart from the mentioned setae a number of ventromedian teeth. Dimensions : d': 5,44 mm; a. = 68; ~ = 8,07; 'f = 24,7. FILIPJEv's formula : o M _ _ P. Dimensions : ~ : 5,68 mm; a. = 57; ~ = 8,7; 'f = 24,4; FILIPJEV' s formula : DE MAN's: d' : 5,55-5,60 mm; 3 ~ ~ : 6,48, 6,59, 'f = 28,5, 30, 28; FILIPJEV's : d': 6,7 mm; ~ : 6,7 mm; a. = 70; a.= 63; a. = 66-66,i; ~ = i0,3-9,3; 7,45 mm; a. = 75,4, 80,3, v. = 68,3, 67,4, 70,8 %. ~ = ii; ~ = ii; v. = 68,i % 'f = 35. 'f = 48; v. = 63, p.. 'f = 28,3-30,4. 77,6; ~ = i0,6, A comparison of the foregoing data proves, that the dimensions of the specimens observed by DE MAN and me fall in the same range of variation. Those of FILIPJEV distinctly deviate from the general trend, especially in respect i0,8, ii,8;

61 FREELIVING MARl E NEMAS OF THE MEDITERRANEAN 63 with the comparative length of the tail which is distinctly shorter in the Black Sea females than in ours. Moreover we find a distinct praeanal wart in FILIPJEv's f.em~le a?d a rather obvious gubernaculum, that I miss in my specimens and IS likewise not depicted by DE MAN in his, that makes me doubt if FrLIPJEv's specimens are conspecific with mine and those of DE MAN. A B A B D FIG. 27. Metoncholaimus demani (ZUR TRASSE.'\). A : Female head. B : Demanian system. C : Female tail. D : Male genital armature. E : Male tail. FIG. 28. Prooncho~aimus mediterraneus SCHUURMANS STEKHOVEl'l. A : Female head. B : Female tail. C : Male head. D : Male tau. Head rounded anteriorly, slightly set off from the remainder of the body. Lip with distinct although not very prominent labial papillae. Cephalic setae comparatively thick and stout; the longer submedian setae measure 26 %, the horler 22 % of the corresponding cephalic diameter. The longer subventral tooth reache till slightl in front of the cephalic setae or to 83,5 % of the buccal cavity, which is twice as long as its greatest width, the shorter teeth measure 61,5% of the length of the buccal cavity. Some short and thick setae are found in the oesophageal region of the body. Amphids at the level of the shorter teeth, 5

62 .T. H. SCHUURMANS STEKHOVEN JR. cupshaped, 25 % of body diameter. Buccal cavity wide, like in M. pristiurus, the shorter teeth are connected by means of a strong cuticular rim. Excretory pore at 1, 76 times the length of the buccal cavity from the anterior end of the body, in FILIPJEv's male at 2, 75 times this distance. Nerve ring in the male almost halfways the oesophageal length, in the female in question at 47,4 % oesophageal length from the anterior border. Spicula long, outstretched, not knobbed at the proximal end, 8 times as long as the anal diameter. There arc 5 praeanal setae along the medioventral surface of the body, whereas the curved tail presents 11 pairs of minute postanal setulae and a small seta near it apex. Female tail gradually tapering with its distal 3/ 7 more or less cylindrical; length of tail 5,6 times the anal diameter. Osmosium of the intestinal efferent iluated almost at the apex of the efferent. Length of male tail 6 times a long as the anal diameter. In the present species the pores of the Demanian system are separated from the anal opening by a distinctly greater distance, i.e. more than twice the anal diameter, thim in albidus BASTIAN, where thi distance i not et quit one anal diameter. In this respect the present species is in ac ordan e with the data of FILIPJEV ( ). A revision of the Black ea material in respect with the mentioned differences i necessary, becau e I am not quite convinced that FILIPJEv's demani is conspecific with mine. My p cimen however undoubtedly belong to the same species as was found in the Ba. of Naples both by DE MAN (1878) and by ZuR!STRASSEN (1894). GEoGRAPHICAL DISTRIBUTION : Mediterranean, Naples, Villefranche. After what may be concluded from the rather incomplete figure made by DE RouviLLE (1904) and found in the bequest of the late DE IA I come lo the conclusion that one of the males observed by DE Ro VILLE at Cette like' i e did belong to M. demani ZuR STRASSEN. Its occurence in the Black ea r mains doubtful. Genus PROONCHOLAIMUS MICOLETZKY, Proonc.holaimus mediterraneus ScHu R 'lans STEKHOVE ', Syn. Pr. megastoma MICOLETZKY nee EBERTH. (Fig. 28, A-D.) 1 cf, from Villefranche, off the " Plage des Marinieres n, coarse sand under vegetation of Posidonia. Depth 3m. 1 <j?, 2_juv. from Villefranche, " Baie de Lilong " sand. Depth 5 m. Dimensions : cf : 3,796 mm; a. = 31,6; ~ = 6,4; y = 29,6. FILIPJEv's formula: 0 1 ~_ 0 _-:o_4_8 s8 ~-~8 5_68 3_!~ P.. 32

63 FREELIVI G MARINE NEMA OF THE MEDITERRANEAN 65 Dimensions : ~ : 3,676 mm; a. = 27,8; ~ = 6,9; y = 17,6; v. = 73,1 %. FrLIPJEv' ~ formula: Juv. FILIPJEV's formula: Dimensions : p P. Length juv. : 2,332 mm; a. = 32,4; ~ = 5,4; y = 14,2. mega toma MrcOLETZKY, Naples: d' : 3,6 mm; a. = 40; ~ = 5,7-7,3; y = (doubtful if belongingto the same species as that of Villefranche (Confer relative dimensions). d' : 2,9 mm; a. = 25; ~ = 6,5; y = 20,6 (a. and ~ not differing very much, apparantly the same species as that of Villefranche). ~ : 3.3 mm; a. = 27; ~ = 6,9; y = 19; V. = 75 %, same species as that of Villefranche. nforlunately MicOLETZKY (1923) ha given neither figures nor extensive data about hi pecimen. Therefore it i not po ible to be ab olutely certain about th iden til of hi pecimen. It would intere t me particularly to kno,, the relati e dimen ion of the buccal cavit of hi pecimens and how this is di ided into two portion b the cuticular band from which the smaller teeth originate. I am ho' e er of the opinion, that apart from his variety neapolitana, of which onl er incomplete data arc known, MrcoLETZKY apparently ha met \vith the true megastoma and with the arne species, which I have ludied aft r the illefran he material, which I might name Pr. mediterraneus. Head rounded an teriorl \ ith 6 lip and indi tinct papillae. Cephalic elae 10 in number, the lono-er one mea uring 16 % of corresponding cephalic diamet r, the horter one no longer than 12 % of the arne diameter, in the male wherea th am etae mea ure 17 % and 10 % of the corresponding Hamel r re pe ti el in the female. mphidial openino- 27,1 % of the corre ponding body diameter in the mal 30 % of the ame in the female, cup haped and in thi re peel differing from that of eberthi, which i almo t circular (due to difference in fixation) fconf r m pap r on freeliving nematode from lexandria (1943)]. Bu cal ca it laro-e in the male, 2,5 time a long a it greatest width (L. = 3 x, id th in male from rice, L. = 2 37 x width in Prooncholaimus eberthi). The bu cal ca it r i ubdivided into 2 eparate cavities, the relative length of which i in the male ex = 1 : 2, in the female ex = 2 : 3, whereas in the mega toma t rpe the relation of both portion = 1 : 1 (male) and in the female of eberthi = 1 : 1,1 o that there exi t a di tinct difference between megastoma t pe and our pecies. The dimensions of the teeth, of which the large

64 66 J. H. SCHUURMANS STEKHOVEN JR. subventral tooth reaches to the level of the cephalic setae in our species as well as in the species eberthi are as follows compared with the female of eberthi : Species Left subventral tooth Right subventral tooth Dorsal tooth eberthi ~ mediterraneus ~ cf Longer subventral tooth 84 %, lower subventral tooth and dorsal tooth 68 % of the length of the buccal cavity in the male of our species. The oesophageal portion of the body further bears some short setae. The excretory pore is found in our male at 1,83 times the length of the buccal cavity from the anterior end. Nerve ring like in eberthi, not like in megastoma EnERTH, i. e. in the male of Villefranche at 53,1 %, in the female of the same habitat at 49,2 % of the oesophageal length, in EnERTn's specimen at 43,1 % of the oesophao-eal length and in the species eberthi on 49,2 % of the oesophageal length. Vulva at almost the same spot in all 3 species. Female tail not swollen at its apex, gtadually narrowing, its distal half almost cylindrical, 5,2 times as long as the anal diameter, width at the apex 0,26 x anal diameter. Spicula long, straight, swollen at the proximal end and provided with a distal prolongation, just as in the spicula of eberthi., as long as the tail, ' hich measures 6,6 anal diameters. The spicules are just as in that pecie, surrounded by the protractores spiculi. Gubernaculum 15 % of the length of the spicula. In EnERTn's male the spicules measured 75 % of the tail length, i.e. 3,7 anal diameters whereas the tail itself is 5,28 anal diameters long; ' idth at the tip 0,28 anal diameter. In the Villefranche male the tail length equals 6,6 the anal diameter, width at the apex 0,41 anal diameter. Male of eberthi, tail 4,3 times as long as anal diameter, width at apex 0,33 anal diameter. The male tail therefore is neither in accordance with that of megastoma nor with that of eberthi. Female tail in megastoma 4,55 anal diameters; width at apex, which is distinctly swollen, 0,22 anal diameter. Female tail in eberthi 3,5 anal diameters; width at apex 0,2 anal diameter. Female tail in the Villefranehe female 4,3 anal diameters; width ~t apex 0,24 anal diameter. The female tail resembles therefore more that of the female megastoma than the male does in respect with the male megastoma, as likewise the division of the buccal cavity of the female is more in accordance with that of megastoma than that of the male.

65 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 67 The attenuation of the body to the anterior is 3,6 in the Villefranche male and 2,55 in the male of eberthi, and similarly 3,66 in the female of Villefranche, whereas it is 2, 72 only in the eberthi female. In the male we find round the cloaca a series of cloacal setae 5 in front of the anus and 4 posterior to the anal cleft, futher there are 2 widely separated subventral hairs and a subventral apical seta. This pilosity is not quite the arne, although very similar to that indicated in the key of MrcoLETZKY (1924) for megastoma (EBERTn). o I come to the conclusion that probably, what MrcoLETZKY thought to be the typical megastoma i at least in part identical with the pecies of Villefranche. ow Prooncholaimus mediterraneus may be distingui hed from eberthi by the tructure and divi ion of the oral cavity and the length of the tail in the attenuation of the oesophageal portion of the body, whereas the species in que tion differ from megastoma proper by the tructure and division of the buccal ca it, the po ition of the nerve ring, the longer spicula as well as by the longer tail, which i le s attenuated in the male sex of our species than in the male ex of megastoma. GEoGRAPIIICAL m TRIBUTIO : Villefranche, Naples, Suez, Alexandria. Genus VISCOSIA DE MAN, Visco ia glabra (BA TIA, 1865). (Fig. 29, A, B.) 7 <j? <j?, 4. juv. from Villefranche, " Baie de Lilong,, sand. Depth 5 m. 7 <j? <j?, 4 juv. from Villefranche off the" Plage des Marinieres n, coarse sand under vegetation of Posidonia. Depth 3 m. 3 cr cr, 1 <j?, 1 juv. from Villefranche, farther end of the " Port de la Darse n, black mud and organic detritus. Depth 3 m. Thi i one of the mo t frequently observed pecie in the Mediterranean. It, a like' i e ob erved by MrcoLETZKY (1923) in many localities, in the Adria, near Japle and in uez. It occur al o in Alexandria. The dimen ion of my pecimens are quite in accordance with those of 11 oletzk for the arne habitat. It i uperfluous to give a redescription of thi wcllkno" n pecie and I ' ill only gi e a figure of the female head and tail end. GEOGR PmcAL DI TR1B TIO : From the Baltic to the Black Sea. Recently al o in the Oresund, further Tarva, Banyuls-sur-Mer, Camargue.

66 68 J. H. SCHUURMANS STEKHOVEN Jn Viscosia elongata FILIPJEv, (Fig. 30, A-C.) 1 r:f, from Villefranche, farther end of the " Port de la Darse,, black mud and organic detritus. Depth 3 m. This species was first described by FILIPJEV after a female from the Black Sea, Anatolia, so that the male is new to science. This male is clo ely related to V. cobbi FILIPJEV (1918) when its genital armature i compared ' ith the genital armatu~ e of that specie. Dimensions : r:f : 2,72 mm; a. = 85; ~ = 5,6; y = 19,4. FILIPJEV's formula: F'Iu:PJEv's female: M , f-l 2,45 mm: a. = 100; ~ = 6,5; y = 18. Head distinct!, set off from the re t of th bod, b a cone lriclion of th body wall. Papillae labiales not seen, probably b cau e th r i a light invagination of the anterior portion of the lip (confer th fon ani po ilion of the cephalic setae, such due to fixation). Cephali eta hort 12,5 % of the corresponding body diameter, al o di tinclly hort r than in th f mal, observed by FILIPJEV, where the mea ure about 25 % of the corr pondincr diameter. Amphids rather large, cup-~haped their openino- 4 % of th corre ponding diameter, therefore much laro-er than in the female, wh r th amphid is minute. This i in o far not remarkable in e there exi l in the closely related Viscosia cobbi a remarkable differ nee in th ize of th amphid between both sexes, tho e in the male being extraordinar larrr, ' hich brinrr a new argument for the fact that the specie are clo el r lat d. Bu al avit, strengthened by rather thick wall, the laro-e ubvenlral tooth rea hino- almo t to the level of the cephalic setae, 12,5 p. long, maller teeth reachincr to the attachment of the larger tooth to the ubven tral wall, 7 p. long (in lh f male the large tooth measures 16 p., the. maller teeth 9 p.). H re ho' er lh interrelations are similar to that in our male, in which the bu cal avil ' i 2,4 lime as long as wide. The buccal cavity of FILIPJEv' female i 1,9 tim a long as wide. Nerve ring in front of the middle ju t as in the female. picule ' ordshaped 1,4 anal diameter long, although less slender than in cobbi. Ju t a in cobbi there are some subventral pairs of cloacal setae, 1 praeanal, 3 po tanal, whereas in cobbi 3 pairs are praecloacal and 1 po tdoacal. Tail o-raduall tapering, then more or less cylindrical, slightly swollen at the extreme apex.

67 FREELIVI 1 I RI E EMAS OF THE l\lediterra EA 1 69 B A A B c A B 29 A B A B ;: FIG Vi. CO ia ylabra (BA TIA.\). A : Iale head. B: Tail. FIG l'iscosia elonoata FILIPJEV. A : lale head. B : r.iale tail. C : lale genital armature. FIG. :H. - n. cosia liracl!ylaima FILII'JEV. FIG Vi co ia macrorhopalocera KREt. A : lal head. B :!ale tail. A : Female head. B : Female tail. FIG i\lcmoncholaimus eleyans KREI. A : Juvenile head. B : Tail. Tail almo ~ l 7 anal diamet r lono', width at apex 0,41 anal diameter. In the femal tudi d b FILIPJEY the len(j'th of the tail wa 9 anal diameter ~ width al extr m apex 0 7 anal diameter. GEOGRAPlll AL DI TRIB TJON : Black '-'ea, ::\Iediterranean Villefranche. From ri co ia cobbi FILIPJE the male in que tion rna be di tinaui hed b it mu h maller ize and by the different arrangement of the cloacal setae.

68 70 J. H. SCHUURMANS STEKHOVEN JR Viscosia brachylaima FILIPJEv, (Fig. 31, A, B.) i juv. from Villefranche, " Baie de Lilong,, sand. Depth 3 m. 1 d', from Villefranche, off the " Pointe de la Gavinett~,, grey mud. Depth 80 m. Dimensions : d' : 1,7 mm; a. = 42,5; FILIPJEv's formula: 0 16 Juv. Length : 1,516 mm; FILIPJEv's formula: 24 ~ = 5,1; a. = 54,1; y = 17.!\I ~ = 4,67; l\ i p p.. y = 12,6. FILIPJEV's females : 2,25-2,57 mm; a. = 33-47; ~ = 5,5-6; y = 13,5-25. Tail 4-4,5 anal diamel r, width at apex 0,44-0,47. Until now the female only was known by FILIPJEV from the furman from a depth of m. Head elongate, rounded anteriorly, with 6 lips, with a man papillal', cephalic setae 25 % of the corresponding body diameter. mphid comparatively small, 30 % of the corresponding diameter, ituated lightl po l riorl" to the apices of the smaller teeth. Buccal cavity elongated, 2,9 time a lona a it is wide. Large subventral tooth reaches to the level of the ephali lac, 16 p. long, smaller teeth 12,8 p.. Ierve ring 57,1 % of the oe ophaacal I ngllt. Spicula almost 1 anal diameter long. Gubernaculum short, membrana ou ~. Tail 5 times as long as its width at the ba e. i ~, GEoGRAPHICAL DISTRIBUTION : Murman Coast, Mediterranean Viscosia macrorhopalocera KREIS, (Fig. 32, A, B.) from Villefranche, grey mud (between the " Lazareth " and " Anse Passable). Depth 50 m. Dimensions : ~ : 1,140 mm; a. = 31,6; ~ = 4,9; y = 14,2; v. =51%. FILIPJEv's formula: Juvenile after KREIS : ,982 mm; a. = 37,8; ~ = 5,1; 16 2S y = 14; 1140 p.. v. = 61,5 %. oa I

69 FREEL TVI 1 G I RJ re NEMAS OF THE 1EDITERRA EAN 7 t The f male in que tion, new to cience, is characterised by the presence of minute cephalic etae, ituated at the anterior border of the lip, which are not harply et off from the rest of the body. Amphid not seen, nor by me, neither by KRE1. Buccal cavity elongate, more or less cylindrical, almost thrice a Ion()' a it i wide, provided with a long, harply pointed ventral tooth, however not quite reaching to the level of the setae. Dorsal tooth rea hing halfwa the length of the buccal cavity. Nerve ring at 60,3 % of Lh oe opha<ycal length. Ovaria double. Tail elongate conical, wollen at the ap., 4,4 time as long as it anal diameter. Length of apical club not quite 1/ 5 of the tail leno'tli. Width at apex 0,31 of anal diameter. GEOGRAPHICAL n TRIB no : Java ea, Villefranche. The pe i in que tio11 clo el re embles V. minor and V. palmre S. S. but differ from the laller by the horter cephalic setae and the minor length of th dar al tooth. Genus MO OCHOLAIMUS KREIS, i luononcholaimus elegans KnEr, (Fig. 33, A, B.) 3 juv. from Villefranche, farther end of the" Port de la Darse», black mud and organic detritus. Depth 20 m. Length j uv. : 2,06 mm; l. = 64,4; ~ = 6,4; "( = i4,7. Tail 7,5 A.D. apex 0,5 A.D. FILIPJEV' formula : fi The juv nile of Lhi pecie re emble rna t 1\l. elegans KnEI to which I think it " ill b corre t to brina the pecimen in que tion. Head rounded ant riorl, pro ided 'vith 6 etae mea urino 26 % of the corre ponding body diam lei" b ide orne other etae next to the ba al end of the buccal cavil., "hi h i 3 5 time a long a it width. Larae ub entral tooth reaching to the 1 v 1 of the cephalic etae. mphid pouch- hapecl, di tinct, opening of the am 1/ 3 of the corre pondino' cephalic diameter, oppo ite to the ba e of the dar al tooth. Tail lon<yate <>Taduall. tapering, with extreme apex liahtly ' allen. 7 5 time a long a it anal diameter. Apex half as' ide a the anal diameter. EOGR PHI AL m TRIB non Bretagne Trebeurden, Iala an archipelago, ill fran he amaraue.

70 72.1. H. SCHUURMANS STEKHOVEN JR. FAMILY ENCHELIDIIDlE. Genus BOLBELLA CoBB, Bolbella hexabulb a FILIPJEV, (Fig. 34, A, B.) ~, from Villefranche, between the " Lazareth, and " Anse Passable,, grey mud. Depth 50 m. Length: 3,49 mm; COBB's formula : a. = 62,2; ~ = 4,77; i y = 21,8; v. = 55,2 % The specimen in question is apparently a juvenile female, the vulva of which was not very pronounced. It could be identified with some difficulty only. Head bluntly truncated anteriorly. Cephalic setae, 6 in number 31,4 % of the corresponding cephalic diameter, attached to the body \ all oppo ite to the apex of the dorsal tooth. Amphids not seen. Oral cavil rather wide. A narrow vestibulum connects the cavity with the exterior. The oral cavity str. s. is subdivided into 3 distinct portions, part 1 and 2 enclo ing a more or less oval space, part 3 being sack-like. The walls of the oral avit arc strongly cuticularized, especially those of the fir t two subdivi ion. One of the two subventral teeth is very prominent, measuring 73 % of the total length of the oral cavity. Dorsal tooth inconspicuous. Posterior to the oral ca ity, the usual birefringent corspuscle, embedded in the oe ophageal ti ue, i observed. No true ocelli visible, but a distinct pigment pot, occup ina alrno t the whole width of the oesophageal cylinder at a distance equal lo twice th length of the oral cavity from the anterior enu of the body. Oe ophaau with 5 bulbi. Excretory pore at a distance equal to 2,45 times the length of the oral cavity from the anterior body end. erve ring at 48,1 % of the total oe ophageal length. Cuticle smooth, almost devoid of setae, except a few near the anterior body end. Tail gradually taperi11g to the more or le finger hapecl posterior portion, which occupies 33,4 % of the total length of the tail which is 3,7 the anal diameters long. Anus prominent. Posterior attenuation of the tail 7,5. Bolbella hexabulba differs from Bolbella cobbi MicoLETZKY from the Mediterranean by the more anterior position of the excretory pore. It position is even more forward than in the allied B. tenuidens CoBB, where the excretory pore is situated at a distance from the anterior end, equal to 3 times the body diameter at a level of the pore. Here this distance is twice as long as the

71 FREELIVING MARINE NEMAS OF THE MEDITERRANEA 1 }3 corresponding body diameter. Moreover the number of oesophageal bulbi is B in tenuidens, whereas there are 6 bulbi of equal size in B. cobbi. Like in B. cobbi the posterior body end bears no setae. GEOGRAPIIICAL DISTRIBUTION : Black Sea, Sebastopol, Mediterranean, Villefranclle. Genus PAREURYSTOMATINA MICOLETZYK and KREIS, Pareurystomatina tenuicauda n. sp. (Fig. 35, A-E.) 1 <j?, 1 <j?, from Villefranche, off the " Pointe de la Gavinette n, grey mud. Depth 80 m. Length, cf : 3,192 mm; a. = 44; ~ = 4,5; y = 11,4. FILIPJEV's formula : ~I HJ2 JJ.. The species is characterized by the long tail with a filiform portion, that occupies 58 % of the whole tail length and is provided with some short setae. Tail 5,92 anal diameters long. Spicula long, curved, bluntly pointed at their di tal end, lightly narrowed at their proximal end. 1 erve ring at 45,5 % of the oesophageal length. Spicular chord 1, 78 anal diameters long. Gubernaculum embracing the distal end of the spicula, provided with a dorsal prolongation, which is 0,64 times as long as the anal diameter. First praeanal ucker 4,3 anal diameters from the anal opening, the second praeanal sucker 3 anal diameters in front of the first. The relation between both distances = 1 : 1,44. Posterior attenuation 14. The corre ponding female measures : Length, <j? : 2,036 mm; a. = 3,4; ~ = 3,3; "f = 11,8. FILIPJEV' s formula : f.l Head rounded anteriorly, separated from the neck by a distinct constriction. Cephalic etae rather long, as long as the corresponding cephalic diameter. Buccal cavity not very deep, 2,35 times as long as its greatest diameter. Cervical setae not longer than 33 % of the corresponding body diameter. Excretory pore not seen. Nerve ring at 47 % of the oesophageal length. Tail almost as in the male, but slightly less effilated than in the latter, 7,5 anal diameters long. Attenuation 15. From Pareurystornatina typicum MICOLETZKY the species at once may be distinguished by its more effilate, flagelliform tail.

72 74 J. H. SCHUUR I N TEKHOVE 1 JR. Genus EURYSTOMATINA FILIPJEV, Eurystomatina ornatum (EBERTH, 1863). (Fig. 36, A, B.) 1 <j>, from Villefranche, off the " Vieux Villefranche n, black mud and organic detritus. Depth 20m. Eurystomatina omatum i aid to occur in Lhe Mediterranean at everal localities. After h coletzky (1923) it hould occur in the Adria a, ell a in the neighbourhood of uez. DE Ro VILLE (1904) tale to have found il al Cette. Now we have to bear in mind that 1ICOLE1',ZKY did non rnize with E. omatum : E. tenue IARIO, E. assimile DE IA and E. filifonne DE 1 FILIPJEV ( ) however did not go o far. lie paral d E. omatum EnERTH which i after him synon rnou ' ith E. tenue MARl from E. a sirnile DE MA with which E. filiforme DE l\i, hould b con pe ifi. Among a collection of ernatode from lexandria I found orne male, which I con ider to be con pecific with E. assimile DE M Durinn- th tud. of these male I carne to the conclu ion that 11 OLETZKY did lik ' i e me l ' ith thi specie at Suez and further that E. omatum and E. a imile are di tin L. At the present moment the genu Eurystomatina i till in ar al onfu ion. This is partly due to the fact that pecirnen of Eury tomatina ar comparatively rare. During the preparation of hi rnonoaraph of Lhe fre li in(}' marin nemas of North Sea and BaiLie cu RM TEKIIOVE am to Lh on lu ion that E. filiforme should be s non rnou with E. a simile DE 1 after FILIPJEV from the Black Sea but not ' ith E. assimile DE 1A from apl Having now to my di po ition a more c Len ive mat rial I hay my opinion and think that FILIPJEv' assimile rniaht be on pe ifi MAN's type. hann- d ' ilh DE A thorough cornpari on of the pre ent female ' ith Lhe fin-ure EsERTn ha given from his type of E. ornatum and an ac ural reading f EBERTn' description convinced me that the pre en t femal ha to be reckoned Lo E. omatum. The same fit for DADAY' pecimen from Fiumc. About the buccal cavity of hi pecie EnERTII ay lilerall (( Pharynx - that i the buccal ca it - ein kurzer mit fe ter hitim anti versehener Cylinder, vom schmalen Oe ophao'us durch eine unten bauchio' Partie shirker abgesetzt, sein vorderer Rand Ieicht O'ezahnt. eine Wand bild t nach innen zuerst eine ringforrnige Lei te und hinter die er z' ei punktforrnin-e Vorspri.inge. An einer Seite erhebt ich ein spitzer Zahn.» The figure EnERTH has given from the anterior portion of the oe ophao'u clearly indicates that there are 3 cro band in the oe ophagu, ' hich i in accordance with what the present female shows. Moreover the di tribulion

73 FREELIVJ G MARINE NEMAS OF THE MEDITERRANEAN 75 of the oesophageal pigment is in accordance with my findings on this female of Villefranche, and as for the pilosity thi similar to that in EBERTa's pecimen. The specimen from Villefranche measured : 5,8 mm; (1. = 69; ~ = 5,25; "( = 48,5; v. = 62 %. CoBB's formula : fl Body of the present female tapering in front, anterior attenuation 3,8. Cuticle ' ilh orne caltered elae, e pecially at the anterior end. Head bluntly rounded anteriorly, where the lip are crowned with one papilla each, 6 papillae in total. Cephalic etae, 10 in number, in erted ju t posterior to the labial ulure, 75 % of the corre ponding cephalic diameter. The smaller etae ol each pair 47 % of lhe lonaer one and 27,5 % of the arne cephalic diameter. Buccal ca il rather deep and broad, 1,62 time a lon g as its widest part, ubdi ided into two inequal portion, of ' hich the po terior is distinctly larger than the anterior portion. Proportion I : II = 13 : 20 = 1 : 1,52. Buccal cavil provided ' ilh three row of bacillary corpu cle. E e ' ith di tinct ocelli, provided with cuticular lenses, situated on a di lance from the anterior border equal to 1,6 times the length of the buccal cavil. 'erve rincr at 34 % of the total oe ophageal length. Tail conical, 2,94 lime a long a the anal diameter ending with a blunt conical tip. Caudal gland di tinct, the cell bodie of the e are located anterior to the anal opening. ince TEINER (1915) gives no figures of his female from Teneriffa it is impo ible to tale if hi pecimen ' a con pecific with the present species. One mu t however bear in mind that the eyes in STEINER's specimen were hifled di tinctl more po leriorad, at 1,92 time- the length of the buccal cavity from the anterior end, ' hich feature rna point to pecific differences. It is hm e er impo ible to bring TEI 'ER's specimen with certainty to one of the kno' n pecie. A for M RIO ' E. tenue thi mea ured 5 mm; a = 79,5; ~ = ~; y = 3,4. Tail 2,45 anal diameter long. Buccal cavity 1,63 times as long a it areate t ' idlh. E e at 2,88 time the length of the buccal cavity from the anterior end. Length of cephalic setae 87,5 % of the corresponding diameter. Proportion of the buccal cavit a for its divisions I : II = 1 : 2, 7. Lenath of the male tail 4 anal diameter. gain we mu t be in doubt just as, ith TEL ER filifonne of T neriffa, if iario ' male belong to the same pecie a EBERTH' omatum. If iarto 's figures have been figured to scale than there mu t be incere doubt, due to the location of the eyes, the lenath of the cephalic,etae and the proportion of the tail, although we are quite uncon iou a to po ible exual difference in thi re pect. So far however I think it wi e not to include E. tenue MARIO in the synonymy of E. omatum. In

74 76.T. H. SCHUURMANS STEKHOVEN JR. DADAY's male (1901, p. 443) the vulva is situated at about 75 % of the body' length therefore in a more backward position than in the present female. Since DADAY's female was not longer than.± 1 mm the identity with our species remains questionable. MicOLETZKY (1924) at least must have intermingled some species, althoug h there were among these almost undoubtedly some specimens belonging to the present species. Of this we cannot however be quite sure, since this author does not give any figures. B 34 A A B D A FIG Bolbella hexabulba FILIPJEV. A : Female head. B : Tail. FIG Pareurystomatina tenuicauda n. sp. A : Female head. B : Female tail. C : Male tail. D : Male genital armature. E : Praeanal papilla. FIG Eurystamatin~ ornatum {EBERTH). A : Female head. B : Tail. FILIPJEv's species from the Black Sea differs from lhe present pecie i.a. by the shorter cephalic setae, the proporlions of the buccal cavity, the situation of the eyes, etc., so that I come to the conclusion that we may state with som certainty that the present species has been found only near Tice, near Villefranche, Banyuls-sur-Mer (ALLGEN, 1942) and Fiume. ALLGEN (1940) ays to have found it along the Norwegian Coast, Hasvik, Vega, Rognsog. I am not sure that ALLGEN's specimens from the Sea of Marmara really did belong to the said species.

75 FREELTVI G MARl E EMAS OF THE MEDITERRANEAN Eurystomatina stenolaima n. p. (Fig. 37.) 1 spec. from Villefranche, " Baie de Lilong,, sand. Depth 5 m. The pecimen i broken, i clo ely allied to E. omatum EBERTH.but may be ea ily be di linguished from the latter by the narrower buccal capsule, which i parll ularly attenuated in its proximal half, as well as by the distribution and lruclure of the buccal teeth and the ab ence of eyes or pigmentpol. Length of buccal cavity 20 p.. Nerve ring at 60 p. from the anterior head end, length of oesophagu 500 p.. Bodywidth at the head end 16 p., at the po terior nd of the oe ophagu 52 p.. Bod tapering in front, width at anterior end 30,75 % of the width at the po terior end of the oesophagu. Lips di tinct, each with a etiform papilla. Cephali tae rather Ion()' and dl tinct, 10 in number, the longer ones 48 % of the corre ponding diameter, the horter ones 45 % of the arne diameter. Amphid oppo ite to the posterior portion of the buccal cavity, circular, large, th ir u iameter mea uring 23 % of the correspond in()' body diameter. Cuticle at the anterior portion of the body with orne setae, arranged more or le in longitudinal rows. Buccal cavity deep, 2, 83 time as deep at its greatest ' id th. Ventral tooth reaching to the upper row of bar-shaped structures, ' herea the dor al tooth is implanted at the level of the econd row of bar-like structures. Relation between the lower and upper portion of the buccal cavil = 1 : 2. Excretor pore at a di lance equal to 2 times the length of the buccal ca ity, with a rather long excretory duct and a di tinct ampulla. Nerve ring at 48 % of the oesophageal length. Length of buccal cavity 4 % of the ' hole oe ophageal length. In the pre ent pecimen no eyes were seen. From Eurystoma tenue MARIO the pre ent specimens differs in the size of it enlral tooth which i distinctly longer than in that pecies and in EBERTn' E. omatum. The arne fits for DE MAN' E. assimile and for E. filiforme DE MA, ' hich and in thi I agree with MrcoLETZKY (1923) are synonymous inter e, but neither with E. omatum nor with E. stenolaimus. The differences Let\ een m pecimen and EBERTH' omatum are indicated above. The species in que Lion rc emble to Eurystomatina longicauda (ALLGEN), which this author ha brou()'ht to the genus Syrnplocostoma, differs from it in the le s attenuate anterior head end and the shorter cephalic etae.

76 78.T. H. SCHUURMANS STEKHOVEN.lR. Genus SYMPLOCOSTOMELLA MICOLETZKY and KREIS, i Symplocostomella mediterranea n. sp. (Fig. 38, A, B.) i )?, from Villefranche, between the " Lazareth» and " Anse Passable», grey mud. Depth 50 m. Length, )? : 4,8 mm; COBB's formula : a.= 48; ~ = 4,86; y = i8,7; v. =58% P. MICOLETZKY and KREIS (1930) have created a new genus for Symplocostomella javaensis with as characteristical features the absence of ocelli and len e and the presence of a row of small rodlets at the border of anterior and po teriot' portion of the buccal cavity. These characteristics were likewi e ob erved in the present species. Head bluntly conical, truncated at its anterior border, the oral pen in 0' surrounded by a cuticularised ring. Slightly more po terior 3 of the 6 labial papillae are observed. Cephalic setae opposite to the apex of the dor al tooth, 10 in number, the paired submedian setae almost equal in length, 31,2 % of the corresponding cephalic diameter. Amphids small, their diameter 13,18 % of the corresponding body diameter, opposite to the posterior fourth of the buccal cavity. Buccal cavity subdivided into two main portions separated by the de cribed circle of cuticularized rods. Proportion of Part I : II = 1 : 2,8, the pac just posterior to this circle of rods being the widest portion of the buccal cavity. Length of the same 2,55 times as long as its wide t part. The anterior portion is again subdivided into three subdivisions by means of cuticularized ring, the posterior of which presents two heigher-shaped cuticularization. The longer of both subventral teeth reaches almost to the level of the crown of rodlets. It is bluntly pointed, whereas the apices of the other teeth are broadcut. At the base of the buccal cavity the usual birefringent cuticularization are observed. Neither lenses, nor pigment spots are present. The anterior portion of the body presents irregular rows of rather small and short setae, whereas a group of 3 setae is found near the base of the buccal cavity. Excretory pore on a distanc~ from the anterior end equal to 1,62 times the length of the buccal cavity. Nerve ring at 39 % of the oesophageal length. Length of the oral cavity 3,65 % of the total oesophageal length. Tail conical tapering to the filiform apex, which occupies 58 % of the total tail length, which equals 3, 76 anal diameters. Anus proeminent. From S. favaensis MICOLETZKY-KREIS the present species differs by the more posterior position of the excretory pore, the more truncate head and by the shape of the tail.

77 FREELIVL G MARINE EMAS OF THE MEDITERRA EA1 79 Genus ENCHELIDIUM EHRENBERG, Enchelidium acuminatum EBERTH 1863., (Fig. 39, A, B.) 1 cf, 1 juv. from Villefranche, off the " Plage des Marinieres, coarse sand under vegetation of Posidonia. Depth 3 m. ' It is not without some doubt that I bring both specimens, originating from the arne habitat to this species. It is a well known fact, to which MICoLETZKY and KREI (1930) have paid special attention, that in many Enchelidiidae males and female present strong sex dimorphism. This is true for instance for Catalaimus and Enchelidium, the female of which was long since indicated ' ith the generic name : Symplocostoma. MrcoLETZKY and KREI (1930) think that E. acuminatum EBERTH should be con idered to be the male of S. pauli MARIO. If this would prove to be true than S. pauli would fall into the synonymy of Enchelidium acuminatum. If howe er MrcoLETZKY's observation about S. pauli MARION are correct (1923) and if he ha not fu ed, a I uppose he has done, the species S. marioni and pauli which a to my opinion are distinct, then it is quite sure that our species i not con pecific with S. pauli, because the opening of the excretory pore is, iluated eli tinctly more forward in MrcoLETZKY's species than in the present form. 1 o I am inclined to bring both specimens which I think are conspecific alth ugh the how orne differences, the value of which cannot be determined ' ith ufficient certainty, to EBERTH's Enchelidium acuminatum, because I am convinced that the male in question is conspecific with that of EBERTH's species. Length of the male in question : 1,276 mm; a. = 79,5; ~ = 4,64; y = 31,5. EBERTH's male: 3 mm; a. = 30: ~ = 5. COBB' formula of male : f'- Juv. lenght : 1,848 mm; a.= 46,2; ~ = 3,32; y = 12,4. COBR' formula : IJ Like in all peeie of Enchelidium the male does not possess a buccal ca it. nterior body end bluntly rounded, the last part more or less cylindri al, followed b a hallo w constriction. Head provided with 6 labial papillae and a much rather long eephalic setae, of which the lateral ones measure 67 % of the corre ponding cephalic diameter and the submedian ones 60 % of the arne diameter. mphid transverse with a wide slit; diameter of the latter half the width of the corre ponding cephalic diameter. Eyes distinct, their piament pot at a distance equal to 1,72 times the cephalic diameter at the level 6

78 80.T. H. SCHUURMA IS STEKHOVEN.Tn. of the cephalic setae posterior to the anterior head encl. Anterior portion of the body with some small setae, placed more or les in rows. Excretory apparatus opening by means of a short excretory duct just posterior to the eyes, al a distance equal to 2,5 time the cephalic diameter at the level of the cephalic setae. End of excretory cell 1,29 times the length of the oesophagus behind the anterior end. In EBERTH's male the same value was 37 A A FIG Eurystomatina stenotanna n. sp. FIG ymplocostomatella medilerranea n. sp. Head end. A : Female head end. B : Tail. FIG EncneLidiurn acurninatum EBERTH. A : Male head end. B : Tail. 1,32 times the length of the oesophagus. Nerve ring at 27,5 % of the oe o phageal length. Tail gradually tapering to a more or less cylindrical portion, which was however less slender than in the fi gure EBERTH has given from the tail of the same species, 4,3 times as long as the anal diameter and ending with a conical tip. Spicula rather slender, curved, 0,64 times as long as the tail, 2,72 times anal diameters long. Gubernaculum mall, 0,36 time the anal diameter, provided with a small manubrium at its proximal end. There are seven rather inconspicuous praeanal papillae.

79 FREELIVING MARl JE _ IEM $ OF THE MEDITERRA rea r 8i The juvenile specimen differs from the male in that it pos es es a di tinct bu al ca it, ' ilh a long ubventral tooth, which distinctly project into the anterior portion of the buccal cavity and i blunll_ truncate. pparentl there i a mall ba al tooth at the dor al side, ju t a in S. marioni after FILIPJEV ( ). 1IcoLETZKY (1924) mention to have found the female of Enchelidium acuminatum EBERTn near uez. Thi female mea ured 2,6 mm in length, a = 45,5; ~ = 4,85; y = 19. End of the excretory cell at 152 % of the oesophag al length, therefore much more caudad than in EBERH' and my male. MrcoLETZKY men lion for E. acuminatum the pre ence of 10 cephalic setae, ' herea EBERTH di lin ll fio-ure 6 cephalic etae onl, the arne number a m p cimen did how. nfortunately MrcoLETZKY (1924) has given no figure o that it i impo ible lo late the correclne of hi ob ervation and if hi pecim n from the Iediterranean were actuall con pecific with tho e of uez. I doubt ho' ever that Enchelidium subrotundum (EBERTH) and Enchelidium acuminatum EBERTn are reall con pecific like FILIPJEv ( ) and MJCo LETZKY beli ve. o the head of E. subrotundum i di tinctly swollen anteriorly, the bod pilo it eem to be more con picuou than in E. acuminatum, ince the body elae are figur d by EBERTH a to attain the arne length a the cephalic eta, ' hich feature cannot be pure fanta y, ince one may be rather certain that EBERTn ha compo, ed hi figure, with great care. And thirdly the gubernaulum of thi pecie although mentioned in the text wa certainly le di tinct and le trong than in acuminatum. o oppo ite to FrLIPJEV and MrcoLETZKY I think that both E. subrotundum and E. acuminatum are good pecie. Enchelidium pauli ( IARIO ) var. denticulatum i not conspecific with E. acllminatum EBERTH and better hould be con idered a a eparate species, the name of, hich hould be E. denticulatum. EOGRAPmc L m TRIBLTIO : Nice, VillE'franche, Naple ~ Suez ~ Enchelidium lon"'icolle FTLIPJEY, (Fig. 40, A-D.) 1 juv. spec. from Villefranche, off the " Plage des Marinieres n, coarse sand under vegetation of Po idonia. Depth 3m. juv. from Villefranche " Baie de Lilong " Depth 5 m. Length of juv. 1 : 1,48 mm (1 = 46,2; ~ = 3,32; Y = 12,4. FILlPJEv formula : 0 12 Length of juv. 2 : 2,6lt4. mm; FILIPJEV' formula : a= 44; p.. ~ = 4,4; y = 12, fl.

80 82.T. H. SCHUURMANS STEKHOVEN JR. Enchelidium longicolle FILIPJEV was created by FILIPJEV ( ) as a new species. No'" lvh coletzky and KREIS (1930) think and in this they are certainly correct, that the females of Enchelidium species are shaped as forms belonging to the genus Syrnplocostoma. W e do however posse already the species Symplocostoma longicolle BASTIAN of which female as well as male are known. So it is rather certain that the preseut species has to change it name in the future, as soon as females of this species will be known. Then the present could get for instance the name Symplocostoma jilipjevi.. A B c D 40 FIG Enchelidium longicolle FILIPJEV. A : Juvenile head end. B : Tail. C : Juvenile head. D : Tail. FIG Enchelidium 11auli (MARION). A : Female head end. B : Tail. MICOLETZKY (1923) synonymizes Symplocostoma tenuicolle EBERTII and S. longicolle BASTIAN after FILIPJEV. He doe not mention however E. longicolle FILIPJEV, the tail of which distinctly differs from the tail of FILIPJEv'. longicolle in the male as well as in the female sex. I have already pointed to the fact, that as to my opinion EBERTn's Enchelidium tenuicolle i not identical with Enoplus (Symplocostoma) tenuicollis EBERTH, for which I have propo ed the name S. paratenuicolle, see below. The present pecimen should be considered after my opinion as juvenile specimens of FILLPJEv' Enchelidiurn longicolle. Head end bluntly truncate, provided with 6 minute labial papillae. Cephalic setae, 6 in number, measuring 58 % of the corresponding diameter in the specimen from Villefranche, even 68 % of the same diameter in the specimen

81 FREELIVI G MARINE NEMAS OF THE MEDITERRANEAN 83 from Baie de Lilong. Head eparated from the body by a distinct con tric Lion. Amphid tran verse, elliptical situated in between the first and econd portion of the buccal cavity, their width equal to 21,5 % respectively 26,4 % of the corre ponding diameter. The buccal cavity into which a hort ve tibulum leads and which is thrice a lona a its greatest width is divided into 2 unequal parts by a cuticularized rin a, which pre en l at the ame time erie of longitudinal bars. Thi ring subdivide the buc al cavity into 2 portions which stay in relation to each other a 1 : 2,85 in both pecimens. Just posterior to the buccal cavity there are di tinct birefrino-ent bodies in one of the pecimens, wherea in the other the e bir fringent boclie are followed by longitudinal pigmentspots, indicating au ocellu. orne minule etae are to be found at the anterior portion of the oe ophagu.. Excretor. pore at a di tance equal to 3,88 times the lenath of the hue al avit (Villefran che pecimen) or (in the Lilong pecimen) equal to 2,95 th arne di Lance from the anterior end, followed by a long duct and a 1i tin t ampulla. Ier ring at 42,2 % (Villcfranche pecimen) or 47 % (Lilong pe imen) from of the oe ophaaeal length. Tail elongate conical, 5 time a Ion rr a it anal diameter. EOGR.\PHIC L m TRlB TJO : Black ' ea, _ Iediterranean, Villefranche Enchelidium l}auli iario, 1870). (Fig. 41, A, B.) 1 ~, from Villefranche, off the '' Plage des Marinieres " coarse sand under vegetation of Po. idonia. Depth 3 m. Dimensions : Length : 5,716 mm; FTLIPJE ' formula :!ARIQ, 's : 0 24 j, Length: 5 mm; FILJPJEv's : rt. = 47, rt. = 41; ~ = 5,35; y = 27,5; i ioo i20 68 ~ =?; y = 33,5. 57i6 f-l ~ (. marioni), 5 33 mm; X= 43; ~ = 6; y = 34; v. = 56,3 %. v. =54 %. MICOLETZKY and KREI (1930) have brought S. pauli to the genus Enchelidiurn, ince they found the male of their S. pauli ar. denticulatum which allhouah a cordino- to me eli tinct from S. pauli, i a clo ely related specie. In 1924 l\lrcoletzky had synonymized S. pauli and S. marioni (FILIPJEv). In Lhi I do not agree ' ith m predece or. l\hcoletzky' female from the Adria mea ured on the a erage 3,24 (1,7-4, ) mm a = 36; ~ = 4,5; y = 17,3 (9-24); V. = 54,4 %.

82 84 J. H. SCHUURMANS STEKHOVEN Jn. My female tapers distinctly to the anterior end, where it is only 25 % as wide as at the posterior end of the oesophagus. Head end bluntly truncate. Labial papillae setiform, 6 in number. Cephalic setae : 10 (2 fused crowns), the submedian setae paired, the longer ones 38 % of the corresponding diameter, the shorter setae 26,2 % of the same diameter. Amphids distinct, although rather small, width of their orifice 16 % of the corresponding diameter opposite to the middle of the buccal cavity. Buccal cavity elongate, distinct]y narrowed to the posterior end. Greatest width 41,5 % of the length, which is 40 micra. Excretory pore almost immediately behind the posterior end of the buccal cavity, at 48 micra from the anterior end, followed by a long pore and a di tinct ampulla. Birefringent bodies opposite to the lower end of the buccal cavit. Anterior end with some short setae, placed more or le in longitudinal rows. I was unable to find the three hort setae, mentioned b hcoletzky a present in this species and reminding at a similar row of hair in the genu Anticoma. Nerve ring at 32,5 % of the whole oesophageal length. Tail conical, soon tapering to a filiform portion, which i li()'htl v olle11 at its posterior end. Length of tail equal to 3,87 time the anal diameter. Filiform portion occupying almost half the length of the tail. MICoLETZKY mentions in respect with his specimens of the Iediterranean that the excretory pore is nearer to the anterior end as 2 time the length of the buccal cavity. In my specimens the distance is almost equal to that in Enchelidium denticulatum. The species in question is clo el allied to Symplocostoma marioni FILIPJEV, like I could tudy it from lexandria. The structure of the buccal cavity of that pecies differ in that it doe not po e s the row of longitudinal rods found at the brink of the second portion of the buccal cavity, in the structure of the buccal teeth, wherea the amphid ha e a more forward position in S. marioni in comparison with E. pauli. GEoGRAPHICAL DISTRIBUTIO ' : Marseille, Iice, Black Sea, eba topol, eapel and Ischia, Adria, near Rovigno and Melada and Bocche di Catarro, Suez. Genus CATALAIMUS CoBB, Cata.Iairnus eberthi (DE MA, 1878). (Fig. 42, A-D.) 1 cf, from Villefranche, " Baie de Lilong " sand. Depth 5 m. The ma]e mentioned under the heading undoubtedly belong to the species described by DE MAN as Enchelidium eberthi. As for the female I am ]e s certain, although the pilosity at the anterior end, the structure of the buccal cavity as well as the spot, where the excretory pore opens to the exterior, points in the same direction.

83 FREEL! JJ\G MARIJ\E ~Ei\I OF THE :\IEDITEH.R J\EA:\ 85 the other hand there are orne difference, o for in lance the fact, that in the female no more lhan 6 ephalic elae could be di covered, whereas th f mal of a Catalaimus peci. norm all po. e 10 cephalic setae; more ver Lh Lail of lh pre. ent female i le ffilate than that of the male. I am how r inclined lo uppo e that the aforementioned male and female belona lo one and Lhc. arne pecie, in which ca e lhi pecie would bel_ong A B D A B 43 FIG. 4:2. - Catalaimu ebertlti (DE!II&'\). A : l\lale head. B : 1ale tail. C : Female bead. D : Female tail. FIG ymploco toma paratenuicoue n. nov. A : Female head end. B : Female tail. to the aenu Catalainw and not lo the genu Enchelidium. At the other hand :\hcole'dzkl and KREl (1930) haye brouo ht and I think with aood rea ~on tmploco toma sabulicola FILIPJEY to the o enu Catalaimus and in thi pecie the female at l a l- the male i nol kno\yn - i in the pos es ion of 6 cephalic tae. The female in question i. indeed clo cl~ related to, if not identical with FILIPJEv' abulicola. If further re earches \\ ould pro\ e the correctne!'; of my uppo ition that the forenamend. male and female belong to one and the arne pecie, then. abulicola mio hl b a ynonym of Catalaimu eberthi.

84 86 J. H. SCHUURMA rs STEKHOVEN JR. Length of the male from Villefranche : ~ : 2 252mm; ct.= 40,2; ~ = 4; y = 1i,3. COBB's formula : l\ p.. cf after DE MAN : Length 2,085 mm; ::J. = 4i; ~ = 5,08; y = i2,3. The slightly wollen head i blunt!. rounde] at the anterior end and demarcated ao-ainst the remainder of the bod" by a con Lri Lion. hallo' pit leads into the rudimentary alimentary anal. I aunt d 6 labial papillae and 10 cephalic etae, the paired ubmed ian eta b ina- un qual in 1 noth, Lh, longer ones m ea uring 53,2 % of the corre pondino- phalic diam l r the horler one 26,75 % of the ame diameter, being onl half a lon o- a th fir t. On the oesophageal portion of the body the rath r numerou horl eta are more or le, arranged in irregular row~. mphidial op ning tran ver lit, 38,4 % of the corre paneling diam ter, ilual d halfway b tw en th anterior border and the e e. The pigment p t ar I no-at tl ' al pr vidrd with roundish lense. Excretor" apparatu ' ith a mall ampulla and excretor duct. The latter open ju t po L ri r to lh e at a dl tan the anterior border equal to 2,45 time the wide L ephali diam t r. ring at 51,8 % of the oe ophageal leno-th. Tail rather broad at ba e, qui kly taperin o- to th Ion o- filiform ap x, 6,8 anal diameter lon o-. The filiform porti n o cupi 63,2 % of th ' h l tail. Spicula, lightly ' allen at their proximal part, it h rd 2 55 lime as long as the anal diameter or 37,75 % of the ' hole tail I no-lh. ub rna ulum small, inconspicuous. Round the anal ap rture one find a numb r of rninul setae, situated on papilla-like elevation one in front of th anu~ two on the postanal elevation of the bod, " berea, further forward a nurnh r f praeanal papillae are ob erved, of ' hich the figure depi t 5 in all. DE ~IA ha f und in his specimens from Naple only 6 cephalic etae he a, not to hav the gubernaculum, ' hich indeed may have e capecl a il. hi The number of praeanal papillae wa even in hi pecim n, whi h i on more than in ours, if the setiform papilla, ituatccl j u t in fran t of the anal l fl, considered as a praeanal papilla, with ' hich it ccrlainl h mologou Length : ~, i,824 mm; :J. = 45,6; ~ = 3,86; y = i2; v. = 5' %. FILIPJEv's formula : i072 i p.. Head rounded anteriorly, without di tinct papilla ino-le cro' n of 6 cephalic setae only, mea uring 14,7 % of the corresponding bod diameter. Further some minute setae along the anterior end, more or le dltr~buled in

85 FREELIVI rg MARl re EMAS OF THE MEDITERRANEAN 87 longitudinal rows. Amphids transversely oval, 26,4 % of the corresponding diameter, opposite to the upper third of the ventral tooth. Birefringent corpuscles at the posterior end of the buccal cavity. Excretory pore just posterior to the buccal cavity. Excretory duct long, ampulla obvious. Buccal cavity with a rather broad vestibulum. Buccal cavity 2,12 times as long as it is wide. Ventral tooth obliquely cut at its distal end, which reaches to the implantatio11 of the cephalic setae. Ierve ring at 51,5 % of the oesophageal length. Tail elongate conical with a fin gershaped prolongation, 6,2 times as long as its anal diameter. Apical attenuation 4, 75, the tail at apex being 21 % as broad as at the anal diameter. GEoGRAPUJCAL DISTRIBUTIO : Mediterranean, raples, Villefranche. Genus SYMPLOCOSTOMA BASTIAN, Symplocostoma paratenuicolle nom. nov. (F.ig. 43, A, B.) 1 <;?. from " Baie de Lilong " sand. Depth 5 m. Length : 3,804 mm; a.= 57,2; ~ = 3,48; y = i4; v. =55%. CoBB' formula of the female I have brought under the same heading v =55% I fir t have brought thi female to the same species as the foregoing male Lelon a lo, because it has a imilar tail, econdly because we know that the female of the genus Encheliditun have an oral cavity distinctly divided into 4 portion b cuticularized rings and by the presence of distinct subventral teeth. A divtinct difference with the male in question I may point to the presence of 6 cephalic etae instead of 10 and the more posterior position of the excretory pore. Head truncated at the anterior end, with rather wide oral opening. Six rather inconspicuous labial papillae and 6 cephalic!';etae, 30 % of the correspondina cephalic diameter. mphids opposite to the second portion of the buccal cavit. Just posterior to the latter the head is slightly constricted. Buccal cay it strongly cuticularized, the long subventral tooth truncate at i.t tip. t a level " ith the tip of the tooth 'lye find a row of small cuticularized rod. Just po terior to the buccal cavity the oesophageal cylinder contains the birefrinaent corpu cle followed immediately by an oval pigment-spot, thus giving the impre sion of an ocellus. Oesophagus with distinct cuticular lining. orne body setae irregularly scattered over the anterior portion of the body. Outlet of the ventral gland opening at a di tance from the anterior border equal to 3 times the length of the buccal cavity. Nerve ring at 25 % of the oe ophageal length. Vulva with distinct vulvar glands. Tail long and

86 88 J. H. SCHUURMANS STEIUIOVEN JR. slender, 8,25 anal diameters long, gradually tapering to the long filiform end, which occupies about 63 % of the whole tail len gth. Some short setae are observed mainly along the ventral surface of the sam e. GEOGRAPHI CAL mstrib UTIO ' : Mediterranean, Naples, Villefranche. DiscussiON : I come to the con clusion that the co ncern ed female might be identical with DE MAN's Symplocostoma longico lle BAsTIA Length of the female of DE MAN : 3,820 mm; :x = 60,8; ~ = 4,45; y = 16 ; V. = 55% Length of buccal cavity 1/ 57 of Oesophagus, 1/ 44 in my specimen. Excretory pore at a distance from the anterior border equal to 5,3 time1:i as long as the buccal cavity, therefore more posterior to that in m pecimen. Length of cephalic setae 90 % of th~ corresponding cephalic diameter. Length of the tail 8,7 times the anal diameter. If both specimens that of DE MAN (1878) and mine are on pe ific and at the same time identical with the forementioned male than th pecie in question should be called E. tenuicolle EnERTn and E. eberthi ( = Catalaimus eberthi) would fall in the synonymy of that spe ies. GEoGRAPHICAL DISTRIBUTION : Nizza, Villefranche Symplocostoma ponticum FILIPJEv, (Fig. 44, A, B.) 1 juv. spec. from Villefranche " Baie de Lilong " sand. Depth 5 m. Length : 3 mm; COBB's formula : FILIPJEv's : <;j!, 7,250 mm; ':]_ = 57,5; ~ = 3.95; y = 16, _ fj-. ;;_ = 50; ~ = 4,5; y = 27. Body elongate, cuticle smooth, devoid of setae, bluntly rounded at the anterior end. No labial papillae observed. Cephalic setae 6 in number, 46 % of the corresponding cephalic diameter. Buccal cavity deep and narrow, 4 times as long as its greatest width and at the utmost 1/ 64 or 15,6 % of Ll1e whole oesophageal length. The buccal cavity is distinctly ubdivided inlo 4 loculi of which the first 2. just posterior to the vestibulum are mall, much broader than deep, whereas the third and fourth are almost twice a deep and inter se almost equally voluminous, as the first two. The subventral teeth reach to the second division of the buccal cavity. Oesophagus ' ith birefringent body and an inconspicuous pigment spot. Oesophagus narrow. Nerve

87 FREELIVI G MARINE NEMAS OF THE MEDITERRA EA_ 89 ring at 50 % of the oesophageal length. Excretory cell 1,2 times as long as Lhe oesophagus. Excretory pore at a distance from the anterior end, equal to 5,6 times the length of the buccal cavity or on 32,5 % of the whole body length. Tail gradually tapering to the apex, elongate conical, 5,82 times as long as the anal diameter. Posterior attenuation 0,34. B A A A B B FIG Symptocostoma ponticum FILIPJEV. A : Juvenile head. B : Tail. FIG ymptocostoma filicauda n. sp. A : Head end. B : Tail. FIG Symptocostoma tongicoue B.I.STIA:-1. A : Female head end. B : Female tail. C : Juvenile head end. D : Tail of the same. GEOGRAPHICAL DISTRIB TIO ' : Black Sea, Mediterranean, Villefranchc, Alexandria Symplocostoma filicauda n. sp. (Fig. 45, A, B.) juv. spec. from Villefranche, between the " Lazal'eth " and " Anse Passable», grey mud. Depth 50 m. FILIPJEV's formula : M f.l Length: 0,736 mm; a. = 6i,3; ~ = 5,4; y = 9,65.

88 90 J. H. SCHUURM NS STEKHOVE JR. Body slender, tail filiform. Cutide with a few setae at the anterior end. Anterior end trongly attenuated too. Head blunt! truncated, lip -v ith a cro' n of 6 minute etiform papillae. Cephalic papillae 10 in number, rather long, the lateral ones 60 % of the corre pondino body diameter, the longer setae of the ubmediatr pair 60 %, the horter setae of the am pair 4 % of the corresponding cephalic diameter. mphid more or le circular oppo ite to the middle of the buccal cavity, 26 % of the corresponding bod, diameter. Buccal cavit. long and ' id e, 2,55 time a long a it wid t part. R lation of both portions of the buc al cavity a 1,33 : 1, the proximal part beina the undeepest one. Ventral tooth long and rather acute, reaching to in front of the anterior cephalic etae, or mea uring 76 % of the whol buccal a it,, dor al tooth at the border between the upper and the lm r portion of th bu al cavity. No e es, no birefringent bodi. E ' Cr.tor, por at 1,75 tim th length of the buccal cavitv from the anterior end foil ' d b. a hort e. retor duct and the u ual ampulla. At the same level a the excrelor, por one find in the lat ral lonailudinal field a group of 3 elae, apart from om hort ta ' hi h do n t ur in group together. Tail effilale quick!. taperina to the lona filif rm porti n, which occupie 70 % of the whol tail I ng lh, ' hi h i 9,1 lim. a I no' a the anal diameter. Attenuation 11, th tail at ap 9,05 % f lh anal cliam l r. The specie in que tion i at one eli tingui habl at il l ng filiform tail and the 'vide lender buccal cavil, too elher with lh anteri r p. ili n of lh excretory pore, haped a in Symplocostomella meditel'ranea n. p. ( onf r p. 78) Symplocostoma longicolle BA Tr, (Fig. 46, A-D.) 1 <j?, 1 juv. from Villefranche, off the " Vieux Villefranche ", black mud and organic detritus. Depth 20 m. i juv. from Villefranche" Baie de Lilong " sand. Depth 5 m. Length : <j?, 4,52 mm; FTLIPJEV's formula : Juv. length : 2,484; FILIPJEv's formula : :X = 45,2; ~ = 4,75 ; = 47,8; ~ = 3,22; P. y = 17,4; y = 16, p.. Juv. lengt!t : 1,544 mm; :X = 38,6; ~ = 2,86; y = 9,41. v. = 61 %. Head rounded anleriorl, crowned with 6 cephalic la a loncr a 35 % of the corresponding cephalic diameter. Buccal cavit rather deep, "ilh a circular opening, 2, 78 times a long as ils -v idest diameter. Length of anterior parl

89 FREELIVI G MARl re NEMAS OF THE MEDITERRANEA 9t of the buccal cavity 38,5 % of the total length of the latter. Ventral tooth long and strong, 69,5 % of the total length of the buccal cavity. Just posterior to the buccal cavity there is a distinct ocellus. Oesophageal portion of the body ' ith some scattered setae. Excretory pore at a distance from the anterior end equal to 4 times the length of the buccal cavity. Excretory apparatu with a long pore and a distinct ampulla. erve ring at 26,5 % of the oesophageal length. Tail elongate conical with a rather long fingershaped portion. Length of the tail 5,8 times the anal diameter. It is provided with a few short eta e. This species has a very wide distribution and is found near Gran Canaria uez to the Black Sea, occurs likewise in orth Sea, Baltic, Trondj hemsfjord, 0 lofjord, etc Symploeostoma longiseta n. sp. (Fig. 47, A, B.) 1 juv. from Villefranche, between the " Lazareth " and " Anse Passable " grey mud. Depth 50 m. Length : 1,292 mm; FILIPJEV's formula : a. = 32,3; ~ = 3,4; ii y = 11, P. It i with orne doubt that I bring the species in question to the said genus. There i an indication of a formation of 4 bulbi at the posterior end of the oe ophagu, o that one has to think at the genus Bolbella or Polygastrophora, but thi indication is not very conspicuous. If the species in question!s compared with the other species of SymplQcostoma it i obvious that here the cervical setae are distinctly longer than in mo t of the kno' n pecie of that genus. There is a long subventral tooth. Head more or le rounded anteriorly, with a crown of rather distinct labial papillae. Cephalic setae, 6 in total comparatively long, 89 % of the corre panding cephalic diameter. Buccal cavity twice as long as its widest diameter. Anterior portion 20,75 % of the whole buccal cavity. The long tooth reaches till in front of the cephalic setae. The cervical setae which are inserted just behind the buccal cavity are almost as long as the corresponding diameter. erve ring at 52,6 % of the oesophageal length. Tail rather long, at first cylindrical at its base, than gradually tapering to a rather filiform terminal portion. Length 5,18 times the anal diameter. Attenuation 10,4. Length of filiform portion 1/ 3 of while tail.

90 92.T. H. SCHUURM ANS STEKHOVEN.Tn. Order II : CHROMEDOROIOEA. FAMILY CYATHOLAIMID.IE. Genus LONGICYATHOLAIMUS MICOLETZKY, Longicyatholaimus filicaudatus n. sp. (Fig. 48, A, B.) 1 f:j?, from Villefranche, between the " Lazareth, and " Anse Passable», grey mud. Length : 2,232 mm; a. = 50,6; ~ = 11,6; y = 4,3; V. = 44,6 %. FILIPJEV's formula : f.j. Body elongated with a long filiform tail. Cuticle with distinct lateral fielrls demarcated by 4 rows of larger dots, width of these field 1/ 3 of the body diameter. Submedially each ring bears 3 tran ver e rows of mailer dot. Body only slightly tapering anteriorly. Here the width of the bod i 54,5 % of the greatest body width. Head rounded anteriorly, inconspicuously demarcated again t the remainder of the body. Lips with a crown of 6 labial papillae and a second ro' n of 10 cephalic setae. The latter pre ents 4 pairs of ubmedian etae and 2 lateral setae in total. The longer partners of the submedian couples mea ur 36,8 % of the corresponding cephalic diameter. Buccal cavity with the u ual diadem and a pointed dorsal tooth. Oesophagus hardly broadened po teriorl.. Amphids with 6 X windings, their diameter 47 % of the corre ponding body diameter. Position of amphids just posterior to the insertion of the dor al tooth. Tail conical at base, quickly tapering to the long filiform portion ' hich occupies 4/ 5 of the whole tail. Attenuation 8. Length of tail equal to 25 anal diameters. Tail hardly swollen at apex. L. longicaudatus has amphids with 1 X winding only whereas the amphids of the pre ent specie po e 6 X windings. The species in question is closely related to L. longicaudatus (DE MA ') created by DE MAN (1878) and redescribed by KREIS (1929). DE MA ' had to hi!' disposition a male only, long 2 mm, in which the ~ was 6,8, whereas KREl saw females as ~ell as males. In the latter the 'Y ranged between 5,5 and 7,3 in the former between 6,6 and 7,1. Therefore in comparison the oesophagus of my female is much shorter, whereas the reverse is the case with the tail of the same specimen, which is decidedly longer than in DE MA 's and KRETS specimens.

91 FREELIVING MARl E NEMAS OF THE MEDITERRA EAN 93 From L. tenuicaudatus the present species may be distinguished by the more regular punctation and by the greater number of amphidial windings. From L. heterurus CoBB and L. trichiurus CoBB it may be distinguished by the number of the amphidial windings met the cuticular pattern Longicyatholaimus effilatus n. sp. (Fig. 49, A-G. ) 2 r:j r:j, 7 <j? <j?, i juv. from Villefranche, farther end of the" Port de la Darse, black mud and organic detritus. Depth 3 m. ' Length of a r:j : 2,464 mm; FJLIPJEv's formula : No female measured. 'l. = 47,2; ~ = i5,3; M !'- y = 8,55. Head end blunt. ix eli tinct lips, each crowned with a setiform papilla. The cuticle is tran versely striated and marked with rows of dots and points, of which those on the lateral fields are particularly large and distinctly differ entialed from tho e on the ubmedian fields, where the rows are more dense and the individual dots more close than on the lateral fields. Lateral fields with irregular row of pore, opening to the cuticular glands. Further some catlered etae. Cephalic crown of setae composed of 10 elements in the usual di lribution. etae rather long, the longer ubmedian setae in the male 40 % of the corresponding diameter; shorter submedian setae 30 % of the same diameter, lateral setae 32 % of that diameter. Amphids consisting of 4 windings, 36,7 % of the corresponding body diameter. Buccal cavity shallow with a rather long dor al tooth. From the posterior end of the oesophagus till the anal opening the width of the body remains the same. There are 3 minute praeanal papillae. Spicula rather long and slender. lightly knobbed at their proximal end, pointed at their distal end and pro ided ' ith a longitudinal crest along the sides. Length of spicula equal to 1,5 time the anal diameter. Gubernaculum angular with a long and slender prolongation. Di tal end truncate, with fine dentition along the exterior rim. Length of the gubernaculum 1,34 times the anal diameter. Male tail conical on it ba al 42 5 %, than filiform, slightly swollen at its apex. Medioventral one find a ro' of 8 rather long setae. Female in general as the male. Cephalic setae longer than in the male the lono-er ubmed.ian setae 72 % of the corresponding cephalic diameter, the horter ubmedian setae 46,5 % of the same diameter. Body setae in the oesophao-eal region longer than in the male. Female tail in general shaped as in the male. The conical portion half as long a the tail.

92 94.T. H. SCHUURM ANS STEKHOVEN.Tn. A c D B F FIG Symplocostoma longiseta n. sp. FIG Longicyatholairnus {ilicaudatus n. sp. A: Head end. B : Tail. A : Female h ead end. B : Tail. FIG Longicyatholaimus ef{ilatus n. sp. A : Female head end. B : Female tail. C : Male head. D : Male tail. E : Male genital armature. F : Female head. G : Tail.

93 FREELIVJNG MARl E NEMAS OF THE MEDITERRANEAN 95 Genus METACHONIOLAIMUS n. gen. This genus is clo ely related to Choniolaimus DITLEVSE, differs from the latter in that it pre ent a di tinctl differentiated dotting on the lateral field. The buccal cavity is hallow, without di tinct teeth. Di position of the cephalic etae a in Cyatholaimus. Oe ophagus with a po terior bulbar swelling, which i ho\ e er not ver vigorou. 1 picula curved. Gubernaculum plate-like, haped a in Choniolaimus. Tail effilate Metachoniolaimus pustulosus n. p. (Fig. 50, A-C.) i <j?. from Villefranche, between the " Lazareth, and " Anse passable,, grey mud. Depth 50 m. Dimensions : ~ p. Length : <j?, i,208 mm; '1. = 30,8; ~ = 9,1 ; y = 8,8; v. = 38 %. Head end trunca te anterior! - to faintl rounded. Lips urrounded by minut labial papillae, further at lea t 6 very hort cephalic etae. The large tran r e piral amphid hm 4 X winding, their diameter i 57 % of the corre pondino- bod diameter. Lateral ides ornated with two median rows of laro-e dot, widel paced and eparated from two other longitudinal row~ of lio-h tl finer te lure, b a di tance half that of the distance over which the t\ o row of laro-er dot are eparated. Dor all and ventrally the dot are finer and more regular! paced. Buccal cavil hallow, ornate with a diadem, ' hich can ho\ ever not be analysed further, because the cavity seems to be filled ' ith dirt. Oe ophao-u ending in a faint, incon picuous posterior bulb. Tail lono-ate, conical with a filiform portion occup ing almost half the tailleno-th. pinneret lana, re embling that in Spilophorella mediterranea. orne cant hair ar rattered over the cuticle. Length of tail equal to almo t 6 anal diameter luetachoniolaimu cylindribucca n. ~ p. (Fig. 51, A-C.) 1. d', from Villefranche, entrance of the road, grey mud. Depth 230 m. Dimen ions: 0 H6.M cl p.. Length : d', 0,924 mm; 11 = 29; ~ = 8; y =?. Head cap haped, rounded anteriorly with 6 minute labial papillae and 10 cephali etae at a level ' ith the upper end of the diadem. mp~ids ir ular, campo ed of 4 X winding, their diameter 45 % of the corre pondmg bod diameter. On the lateral sides we find 4 longitudinal rows of dotted 7

94 96 J. H. SCHUURMANS STEKHOVEN.ln. point, alternating with cuticular pores and finer dots, separated by narrower spaces to the dorsal and ventral sides. The mentioned 4 row are widely spaced. On the cuticle orne scanty hair Buccal cavity c lindrical wilh distinct diadem, but without a dorsal tooth. Oe ophagus ending with a di tinct posterior bulbus, far more distinct than in Metachoniolaimus pustulosus. B A c B A c 0 0 (I ~ : FIG \letachoniolaimus pustulosus n. p. A : Female head end. B : Female tail. C : Base or re ophagu. FIG M etachoniolaimus cylindribucca n. sp. A: Male head end. B : Male tail. c : Male genital armature. FIG Paralongicyatholaimus ma tigodes n. p. A B : Female head end. C : Tail. Bulbus occupying 28 % of the oe ophageal leno-th. picula ur d br adl truncate at the proximal end, harply pointed at the di tal nd, almo t 1 anal diameter long. Gubernaculum platelike "ith di tal tooth. Tail at fir l elongate conical than filiform, the filiform portion o up_ ina almo l 2/ 3 f the whole taillength. Tail 8 anal diameter long. The present specie rna be ea il di tingui hed from the form r b. th more circular amphid, the cylindrical bucca} cavil., lhr m re pronounced oesophageal bulb and the longer filiform tail.

95 FREELlVING MARINE EMAS OF THE MEDITERRANEAN 97 Genus PARALONGICYATHOLAIMUS n. gen. This ne\ genu can be distingui hed from the genus Longicyatholaimus by the ab ence of a dor al tooth in the buccal cavity. and bv. the fact ' that the cuticle doe not show pecially differentiated lateral fields, since the punctation on the tran, ver~e row is uniform. Amphids with 5 X windings. Tail di tinctl cffilated like in the genu Longicyatholaimus Paralongicyatholaimus mastigodes n. sp. (Fig. 52, A-C.) 2 ~ ~, from Villefranche, off the " Pointe de la Gavinette " Depth 80 m. Length: 2,668 mm; FILIPJEV's formula : a. =?; ~ = 6.67; i 988 y = 3,92; v. = 45 % P. Head end clf'marcated again t the remainder of the body by a slight constriction. Cuticle uniform! punctate, dotted v ith transverse rows of points. On the lateral field oval pore are cattered beh een the transver e rows of point and connect the e. Oesophageal portion of the body with some setae. ix labia with as many etiform labial papillae. The crown of cephalic elae embrace 10 component, all etae subequal, 45,5 % of the corresponding cephalic diameter. Amphid circular ' ith 5 X windings, 32,5 % of the corre pondino- bod diameter, oppo ite to the lower border of the buccal cavity. Buccal ca it ' ith trengthened ' all a11d a diadem consi ting of about 12 lonailudinal rib. Tail much like that of Longicyatholaimus filicaudatus, quickl tapering to the long filiform portion, which occupies 86 % of the whole tail leno-th. Terminu of the tail not wollen. Attenuation 13. Length of tail 17 time the anal diameter. The pre ent pecie is nearly related to Spjlophora giardi DE RouviLLE found near Cellc,, hich pecie apparent! belollg to the arne genus although it i almo t impo ible to recon truct it after the very incomplete 4escription DE Ro ILLE (1904) ha given from thi pecie. :Similarly it i almost impo ible to get a correct idea of the tructure of this pecies after the figure I have een in the beque t of the late Dr. DE MA, which figure an wers to DE Ro vrli.e' de cription but i ery incomplete.

96 J. H. SCHUURMANS STEKHOVEN.Tn. Genus CYATHOLAIMUS BASTIAN, Cyatholaimus paucispira n. p. (Fig. 53, A-C.) 1 <:j?, from Villefranche, baie de Lilong, sand. Depth 3 m. Length: 3,6 mm; FILIPJEv's formula : (1. = 45; ~ = ii,2; y = 9; v. =55% ~~ 0 Body tapering anterior! at th ulmo t half a "i le anterior! a it maximal width. Head rounded an ler.iorly, not harpl et off from th r mainder of the body. Cephalic papillae liform, 6 in number. Ten ephali etae, the ubmedian pair of etae unequal in leno' lh, lh lon O' r hair m a suring 38,3 % of the corre ponding cephali d.iam lcr. mphid large, circular, consi ling of 2 ;.{ I o e winding, their diameter 35 5 % of th rr : ponding body diameter. Cuticula ' ilh Lran er r w of d L, the cl L demarcating the borders of the rino' di lin ll. fin r than tho ' hich o up, a transmedian po ilion on the cuticular ring. Nerve ring halfway the oe ophageal 1 ngth. Vulva plac I po t riorl y with distinct vulvar gland ; the ul a it elf i trengthened b lono'itudinal cuticularized ribs. Tail elongate, at fir l ylindri al, th n mor fino' r- hap d, the latter portion occupying 41,5 %of the whole tail, v hich i anal diamet r long. Posterior attenuation Cyatholaimus chit.woodi n. p. (Fig. 54, A-C.) i <:j?, from Villefranche, off the " Pointe de la Gavinette,, grey mud. Depth 0 m. Length: 1,608 mm; (1. = 22,3; ~ = 5; y = ii,42; v. = 48,5 %. FrLIPJEV's formula : : i p. 0 The present specie shows much re emblance with Prceacanthonchus punctatus BASTIA and might eventually be reckoned lo that o-enu, " r not th labial papillae of the species belonging lo that genu minute, but pro min n t like in the present specie, where ' e find etiform papillae. Further we do not know how the male i tructured, o that there i rea on to keep the present species in the genus Cyatholaimus till \Ve have more material to our disposition.

97 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN 99 Head rounded anteriorly, demarcated posteriorly by a faint uture line. Cuticle striated tran ver ely b mean of point. Here and there, but e pecially along the lateral fields, placed more or less in rows, one may observe the pores of the unicellular skin o-land. ix tiform labial papillae urround the oral opening. There are 10 cephalic etae, of which the submedian groups are paired. Length of the longer ubmedian hair 31,5 % of the corresponding cephalic diameter, the shorter one 22,7 % of the arne diameter. Amphids circular in outline, but A 53 n A 54 c A 55 B ~ )/ FIG Cyalholaimus paucispira n. p. FIG Cyatlwlaimus chitwoodi n. sp. A : Female head. B : Tail. C : Base of resophagus. A : Female head. B : Tail. C : Vulva. FIG Paraseuratiella brevisata n. sp. A : Head. B : l\lale tail. C : Male genital armature. piral in lruclure itualed oppo ite to the lower border of the buccal cavity, mea uring 27,7 % of lhe corre ponding body diameter. Buccal cavity hallow with a diadem, compo ed of 6 longitudinal ribs. Oe ophagu c lindrical, lighll widened to the po terior end. o oe ophageal bulb pre ent. Nerve ring at 41,3 % of the whole oe ophageal leno-th. The kin bear orne cattered hair a ' 11 in the oe ophageal region a on the tail part of the body. Tail elongate con ical, 2,65 time- a long a the anal diameter. Spinneret di lin t but hort. I have dedicated the pre ent pecie to B. G. and _I. CHITWOOD, the well kno~ n nematologi t. Cyatholaimus chitwoodi re emble likewise C. sunesoni ALLGE, recentl (1942, p. 39) de cribed by thi author from Banyuls- ur-mer. ALLGE 's figure 9.

98 foo J. H. SCHUURMANS STEKHOVEN JR. (p. 39) is rather incomplete with respect to the pilosity of the head end of his species. The arnphids of his species show a smaller number of revolution. ALLGEN states to have found a female but fails to give measurements of the latter. The tail of his male tapers more adruptly than i the ca e with our female. So that we remain till so far more or less in doubt about the question of chitwoodi is conspecific with sunesoni or not. Should laller investigations prove this to be the case, than the present species has to change it name into sunesoni. Genus PARASEURATIELLA n. gen. The genus in question is intermediate between Cyatholaimus and euratiella. Like in Seuratiella the male is in the pos es ion of 4 equal praeanal tubuli. The rubernaculum however, that, in Cyatholaimus, a companie lhe spicula over almost their whole len oth, presents no longitudinal apophy e, but is shaped like a somewhat irregular rectangular plat \ ith di lal tooth-like excrescences. Further the most anterior tubulus i not larger than th three following ones, like in the case in SeUI atia. Buccal cap ule with ut the dorsal tooth, structured ]ike in Cyatholaimus. Punclation uniform, no lateral cliff - rentiations. Ocelli present Paraseuratiella breviseta n. s p. (Fig. 55, A-C. ) i cf, i <.?, from Villefranche, between the " Lazareth, and " An e pa able,, grey mud. Depth 50 m. Length: cf, f,092 mm; FILIPJEv's formula : a. = i7; ~ = 5,7; y = i0, :\ !-'. Length : <.?, 1,072 mm; FILIPJEv's formula : 0 :12 a. = 22; ~ = 7,08; y = 8,92. so : p.. Heau distinct.ly demarcated, in the posse ion of 6 lip. Labial papillar. inconspicuous. Cephalic setae short, the partners of the ubmedia~ groupslightly unequal, 10,4 % of the corresponding cephalic diameter. Amphid rather large, with 5 X windings, circular, slightly po lerior to the bu cal cavity, 38 % of the corresponding body diameter. Cuticle with tran ver e row of rather fine points, whereas the lateral fields are indicated by the numerou irregularly scattered pores of the lateral glapds. Ocelli pre ent. Opening of the ventral gland not seen. In the oesophageal region one finds orne hort setae. Buccal cavity shallow and wide, with a diadem of 12 ribs. Eye present.

99 FREELIVING MARINE NEMAS OF THE MEDITERRANEAN Wt- Nerve ring in the female at 53 % of the oesophageal length. In the male 4 similar equidistant praeanal tubuli, the foremost on 3 anal diameters from the cloaca. Spicula slightly curved, knobbed at their proximal end, pointed at their apex, 85% of the anal diameter long. Gubernaculum with upper edges rounded, lower angles pointed. Tail conical, 2,17 times as long as the anal diameter. Genus PRJEACANTHONCHUS MrcOLETZKY, i Prreacanthonchus micoletzkyi n. sp. (Fig. 56, A-C.) i -d, from Villefranche, off the " Plage des Marinieres " coarse sand under vegetation of Posidonia. ' The species is closely allied to P. punctatus (BASTIAN), which was falsely brought by me to the genus Cyatholaimus in my treatise on the Nemas from the North ea and the Baltic. It may be distinguished from it by the different shape of the proximal end of the gubernaculum, which is undoubtedly more slender in the present species than in punctatus. In punctatus there are 6-7 praeanal papillae, whereas the present species does not possess more than 4 prominent papillae with tubular outlets of the concerned glands and a fifth papilla just anterior to the cloaca, which apparently is a slightly reduced tubulus. The shape of the gubernaculum and spicula, as well as the number and structure of the praeanal papillae strongly resembles the figure KREIS has given from hi pecies Paracanthonchus arcuatus from the Mediterranean, but the present species mi ses the characteristical dorsal buccal tooth, which all pecie of Paracanthonchus possess. Yet I will not exclude the possibility that the present species is identical with the species MrcoLETZKY has named Prceacanthonchus mediterraneus in 1924, which specie he characterized by saying that it differs from P. punctatus BA TIA in that the proximal part of the gubernaculum is paired, whereas it i unpaired in punctatus. But ince fr coletzky has given no further particular of thi pecie, which he promised to describe at a later date, P. mediterraneus must remain a nomen nudum. So I may dedicate the present species to the ' en known helminthologist MrcoLETZKY by naming it p. micoletzkyi, althouo'h there will alwavs remain some probability that the present species is 0 con pecific with the named P. m,editerraneus. Length of the male : i,i32 mm; a.= 28,5; ~ = 6,6; Y = 9,45. F'rLIPJEV's formula : H32 p.. Head eli tinctly demarcated by a suture line. Six lips w~th inconspicuous labial papillae. Cephalic setae rather slender, 33 % of the corresponding

100 .T. H. SCHUURMANS STEKHOVEN JR. cephalic diameter. Amphids consisting of 4 Yz "\vindings, circular, posterior to the buccal cavity, 41 % of the corresponding body diameter. Lateral fields demarcated by rows of larger, more widely distanced dots and rows of pores belonging to the corresponding skin glands; width of the lateral fields 60 % of the body diameter. Excretory pore on 2,64 times the width of the head at the level of the cephalic setae from the anterior end. Buccal cavity rather deep with a diadem of longitudinal ribs. B 8 A A c FIG PrreacanfJwnchus micolet::kyi n. sp. FIG Pr<Pacantlwnchus angulalus n. p. A : Male llead. B : Male tail. A : Male tail. C : Male genital armature. B : Male genital armature. FIG P-rreacanlhonchus uni[o'rmis n. sp. A : Female llead end. B : Female tail. C : Male!lead encl. D : l\lale tail. E : Male gflnital armature. There are 4 distinct praeanal tubuli, separated from each other by almo t equal distances, a fifth is found at the base of the anal promonlor. part from these tubuli one finds in the ventral body sector ome praeanal etac, a well as some longer setae on the ventromedian tail surface. On the tail end one may distinguish much clearer the difference in puuctation between the lateral fields and the submedian body sectors, on which the row of points are more closely placed, whereas the points are here much smaller and finer. Gubernaculum with paired lateral prolongations which are curved lowarcls the head end and an unpaired broadened distal portion that bears some teeth at the

101 FREELIVJNG MARINE EMAS OF THE MEDITERRANEAN 103 anal end, whereas more to the dorsal side of the same small denticulations are visible. Length of gubernaculum 91 % of the anal diameter. Spiculum curved, knobbed at the proximal end, pointed distally. Length of the spicular chord 1,12 times as long as the anal diameter. Tail curved ventrally with a distinct spinneret, 2,5 anal diameters long. MrcoLETZKY (1934, p. 135) supposes that Cyatholaimus quameriensis von DADAY might be a synonym of Prceacanthonchus mediterraneus MrcoLETZKY. In view of the fact that P. mediterraneus is a nomen nudum, I can neither confirm nor deny this supposition. If my figures are compared with those of vo DADAY (Pl. XXI, fig. 4-8) it is rather certain that both species are not identical, confer the dissimilarity of the praeanal papillae in the present species, the peculiar setosety of the tail, etc. So C. quameriensis von DAnAY althoug probably belonging to Prceacanthonchus must remain a questionable species Prreacanthonchus angulatus n. sp. (Fig. 57, A, B.) r:f, 1 juv. from Villefranche, off the " Vieux Villefranche», black mud. Depth 20 m. Closely allied to the foregoing species but differing from it in the structure of the gubernaculum, which is angular, with hooked distal end. Gubernaculum almost 2/ 3 as long as the spiculum embracing the latter at its distal encl. Gubernaculum a long as the anal diameter. Spiculum with a bend, its manubrium rather narrow and hardly headed, followed by a broader piece, which again attenuates towards the tip, 1,1 anal diameters long. There are only 4 praeanal tubuli, accompanied by short setulae, the anterior one separated from the anal opening by a distance equal to 2,64 anal diameters. The fifth reduced tubulus that was observed in Prceacanthonchus micoletzki ScHUURMANS TEKHOVE was not present in this species. Tail angular, curved ventrally, with di tinct pinneret. There are here the same two unequal setae on the mediaventral ide, like I found in rnicoletzkyi. Tail 4 anal diameters long. Head end like in micoletzkyi. Dimensions : Length : r:f, 0,852 mm ;!X= 19,4; ~ =?; y = 10, M 772 i p..

102 104 J. H. SCHUURMANS STEKHOVEN JR Prreacantbonchus uniformis n. sp. (Fig. 58, A-E.) 1 t;!!, from Villefranche " Baie de Lilong,, sand. Depth 5 m. Length: t;!!, 1,272 mm; FILIPJEV's formula : Length: t;!!, 1,2 mm; FILIPJEv's formula: a.= 35 2; ~ = 7, 1; y = 9,i M P. {J. = 30; ~ = 6,65; y = 10; v. = 51,5 % p.. The present species fits best in the genus Prceacanthonchus in the relationship of Prceacanthonchus angulatus from which it may be di tingui hed by its larger size, by the more coarse and truncate tip of the guberna ulum, the broader spiculum. Tail comparatively longer. Dolling hardly more distinel on the lateral sides. Head portion distinctly demarcated by a coustriclion from the remaind r of the body. Six lips. A crown of 10 slender cephalic setae, of almo t equal ize measuring 40 % of the cephalic diameter long. Lips. wollen. Amphid piral their outline circular, with 5 X' windings in the male sex, femal amphid with 4 X' windings only. In the male the diameter of the amp hid equal 57,5 % of the body diameter, in the female it measures only 30 % of the ame diameter. Both amphids are situated at the lower border of the oral cavity. The latter is rather deep, 1,9 times as deep as its greatest width. It i di ided into two equal portions : a vestibulum without trongly cuticularized ' all and a proximal portion with the diadem consisting of 12 longitudinal rib. Oe o phagus cylindrical. Cuticle distinctly ringed, each ring with 4 transver e rows of fine points. Behind the amphids some fine setae. Ocelli mall, on a distance equal to 4 times the length of the buccal cavity from the anterior border in the female sex, and to 5 times this length in the male sex. Female tail elongate conical with a distinct spinneret. Caudal lip of the anal opening swollen. Length of the tail 5 anal diameters long, male tail 4, 7 anal diameter long. Genital armature consisting of a rather slender gubernaculum with bluntly truncate distal end and a bluntly pointed dorsal prolongation. Length of the same 0,75 anal diameter. Spicula angular, with a straight proximal portion and a velate distal end. Length f anal diameter. Four praeanal papillae, the fore most at 3 anal diameters from the anal opening.

103 FREELIVTNG MARINE NEMAS OF THE MEDITERRANEAN ion Genus PARACANTHONCHUS MICOLETZ'KY, Paracanthonchus filipjevi MrcoLETZKY, (Fig. 59, A, B.) 1 d, 1 C.j:>, from Villefranche " Baie de Lilong», sand. Depth 5 m. Length : 1,456 mm; (]. = 20,1; ~ = 7,28; y = 8,85; v. = 60,5 %. FILIPJEv's formula : 0 so 200 sso fj- FILIPJEV's C.j:> measured: 1,3 mm; (]. = 22; ~ = 5; y = 11; v. =51 % The head is distinctly set off from the rest of the body. Cuticle with prominent rings, each with, especially at the lateral borders, 4 rows of small points. Lateral fields indicated by the pores of the skin glands and the short setae. Labial papillae setose Crown of cephalic setae composed of 10 components, the paired submedian setae subequal in length, the longer ones 27,6 % of the corresponding cephalic diameter, whereas the shorter ones mea ure 22,8 % of the same diameter. Lateral setae equal in length to the horter uhmedian setae. Buccal cavity deep, with at least 10 longitudinal rihs of the diadem..ju t like FrLIPJEV (1922) remarks the buccal cavity becomes one- haped po terior to the buccal tooth. Dorsal tooth pointed opposite to the amphid. The amphids, circular in outline, do present 5 X' windings. Diameter of amphids 26,3 % of the corresponding body diameter. Nerve ring at 40 % of the oe ophageal length. Tail elongate conical, sharply pointed to the tip, with three caudal glands in tandem position. Length of tail equal to 3,32 anal diameters. In FrLIPJEv's female the tail measured 3,1 anal diameters. GEoGRAPHICAL Dl TRIBUTION : Black Sea among Cystosira, Villefranche. t C.j:>, FAMILY CHOANOLAil\UDJE. Genus COBBIONEMA FILIPJEV, Cobbionema cylindrilaimoides n. sp. (Fig. 60, A-C.) from Villefranche, off the " Pointe de la Gavinette», grey mud. FrLIPJEv's formula : so ss fj- Length : 1,456 mm; (]. = 16,5; ~ = 6,85; y =?. in e the anal cleft could not be located with certainty the -y could not be determined with accuracy. I doubt however if FILIPJEV has correctly placed

104 t06 J. H. SCHUURMANS STEKHOVEN JR. the anal opening of his species quite near the beginning of the narrowing of the tail. The present species and Cobbionema acrocera FILIPJEV differ especially in the structure of the second portion of the buccal cavity which is here in the possession of particularly thick walls, which apparently may be drawn outwardly at the articulation point, by means of the musculature of the anterior bulb, thus affording a vigorous chewing mechanism for animal preys (o ther nemas P). c A FIG Paracantlwnchus filipjevi MICOLETZKY. FIG Co /1/Jion ema cylinc/rolaimoi<les n. sp. A: Female head end. A : Head end with ce opllagu. B : Tail. B : Anterior head end. C : Tail. Head portion narrowing to the fore border, bluntly conical, rounded at its anterior end. Cuticle regularly Jotted with transverse ro' of point. Amphids almost circular in outline, spiral in structure, with 4 X "inding, opposite to the anterior portion of the buccal cavity, their diameter mea uring 26,9 % of the corresponding body diameter. Crown of cephalic etae anterior in position. There are 10 setae in total, the shorter submedian hairs and the lateral setae are very short and of the same size, whereas the longer submedian hairs surpass the shorter ones by far in length. Longer submedian. etae measuring 68 % of the corresponding cephalic diameter, whereas the shorter submedian and lateral setae measure only 19,4 % of the same diameter.

105 FREELIVING MARl E NEMAS OF THE MEDITERRANEAN t07 Buccal cavity long and complicate, just like in other representants of the same family. The anterior portion which occupies 66 % of the whole cavity is cylindrical, bordered by thick cuticularized walls. These walls are prolongated backwards into broad, sinuous, thick cuticular bars, which serve the attachment of the pharyngeal musculature, which fills up the swollen pharyngeal bulb or corpus pharyngis, which is sharply set off against the isthmus. Posterior portion of the buccal cavity more or less triangular. On the brink between anterior and posterior portion of the same we find a row of denticular corpuscles, like I-lalichoanolairnus also possesses. Lips in the shape of protuberances. The oe ophagus begins to swell again almost immediately behind the short isthmal attenuation, till it attains its greatest width at the junction with the inte tine. Ventral gland short and broad, opening halfways the oesophagus b means of an excretory pore. Tail conical with a long pointed prolongation, that end ' ith a curved spinneret. Some minute setae are found at the beginning of the terminal point. Typical for the genus is that the longer submedian setae apparently belong Lo a more anterior crown of sensory organs than the shorter setae, which build up a po terior crown, composed of exactly six components. The labial papillae, -v hich probably were not seen because of their small size form the third crown. Here the crown of 4 cephalic setae is situated between the crown of labial en ory organs and the crown of six cephalic short setae, opposite to what we find in the genus Dignathonema, where the crown of 4 longer elements is situated posterior to that of the six shorter setae, which proves again that there exi t a hifting of the sensory organs along the head, and that the crown of 10 element in the Cyatholaimidce is due to fusion of the two last crowns of 6 and 4 elements each. GEoGRAPniCAL DJSTRIB TIO : Mediterranean and Black Sea. Genus CHEIRONCHUS COBB, Syn. genus DIGNATHONEMA FILIPJEV, Cheironchus macramphis n. sp. (Fig. 61, A-F.) 1 cf, 1 juv. from Villefranche, off the Station, coarse sand under vegetation of Posidonia. Depth 15m R 12 8 " = 32. Length : cf, 2,5 mm; :s. =, ; l' =,,, FILIPJEV's formula : M Length of the <j? 2560 P. of FILIPJEV's Dignathonema bulbosum : 4,340 mm; a. = 40; ~ = 19; y = 56. F 1 upjev has only seen a female of his species, so that the male brings a wellcome addition to our knowledge of the genus.

106 .T. H. SCHUURMANS STEKHOVEN.Tn. Head bluntly truncate to slightly pointed at its anterior end. Lips with minute labial papillae. Further two crowns of cephalic setae, an anterior crown consisting of 6 short conical, papilliform cephalic setae that measure 16,6 % of the corresponding cephalic diameter and a crown of 4 rather long cephalic hairs, which are 42 % of the corrc ponding diameter long. In total we have 61 c F FIG Cheironchus macramphis n. sp. A B : H ead end. C : Male tail. E : Male genital armature E : Ba. e or ce. ophagn.. F : Tail of larva. therefore 3 crowns of cephalic. en e organs. Cuticle dotted "ith ~ mall poin l, placed in transverse rows. Body setae almo t totally ab ent. mphid r broad, distinctly elliptical, with 4 X' windings, their diam ter 54 % of the corresponding body diameter. Buccal cavity apparently not ver deep, inc the cavity is partly filled up with the buccal armature, con i ling of two large - jaws, placed in the lateral plane. These jaws are supported at each ide by mall prongs, or secondary jaws, which bear at their distal ends irregular club- haperl thickenings. At each side apparently two such prongs are to be found.

107 FREELIVING MARINE EMAS OF THE MEDITERRANEAN 109 Pharyngeal portion of the oesophagus elliptical, swollen, strongly muscular. Isthmus long and narrow. Posterior end of oesophagus sudden becoming bulbar again. Tail short, conical, 1,285 times the anal diameter, truncate at the spinneret. Spicula angular, curved, with a small proximal knob, 1,31 times the anal diameter long. Gubernaculum small, triangular. There are 12 praeanal papillae, the most anterior of which is situated at 5,85 anal diameters from the cloaca. The present species differs from the nearly related Dignathonema bulbosum FILIPJEV [Cheironchus bulbosus (FILIPJEv)] in that the longer submedian cephalic etae are distinctly longer in macramphis than in bulbosus (FrLIPJEv). Further the amphids are much larger and elliptical, whereas the general outline of the same structures in bulbosus is almost circular, like is also the case in Dignathonema norvegicum ALLGEN [Cheironchus norvegicus (ALLGEN)], which was depicted by ALLGEN (1940) after a female with invaginated head end. This pecie wa insufficiently depicted and described. If the shape of the tail is taken into consideration it should be remarked, that this shows far greater re emblance with that of our Cobbionema cylindrolaimoides thim with that of a Cheironchus species, where the tail is short and blunt. As far as the buccal cavity i regarded, ALLGEN's figure lets us quite in doubt, how it was structured in realit. Did ALLGEN really see the peculiar jaws, typical for that genus, or wa the buccal cavity more cylindrical? This we urgently want to now before it is pos ible to make a final conclusion. Genus TROGOLAIMUS COBB, The genus Ttogolaimus is more or less intermediate between Halichoanolaimus and Cobbionema. The buccal cavity consists of two spaces, the first of ' hich is cylindrical like in Cobbionema (in CoBB's Trogolaimus unijormis it wa cyathiform, but this may be due at least mainly to the fact, that in this specimen the buccal cavity was disclosed), whereas the walls of the second pace are trengthened by a number of rodlike longitudinal cuticularized ribs, like ' e find these in Halichoanolaimus. I counted 6 of these. CoBB has found no more than 3. The bars are, like CoBB remarks, crowned with curved cusps. A cuticularized transverse band holds the longitudinal bars together at the junction bet> een first and second portion of the buccal cavity and serves at the arne time the attachment of the muscles. There is a distinct pharyngeal bulblike welling. Tail conical at base, ending in a filiform portion just as in Halichoanolaimus. In Trogolaimus unijormis CoBB describes the tail as cylindrical tapering towards the rounded or conoid terminus. In his specimen the tail wa therefore differently shaped from that in the present form. Further differences are found in the papillashaped structure of the cephalic setae in CoBB' form, whereas the same setae are distinctly hairshaped in ours and in

108 HO J. H. SCHUURMANS STEKHOVEN JR. the absence of body setae in our form, whereas Conn's species presents distinct cervical setae placed backwards from the spiriform amphids. These differences are however not great enough to separate the present form from the genus Trogolaimus and to bring it to a new genus Trogolaimus micramphis n. sp. (Fig. 62, A, B.) 1 juv. spec. from Villefranche, off the" Pointe de la Gavinette n, grey mud. Depth 80 m. Length : 1,712 mm; ~ = 33; ~ = 6,3; y = 8,55. FILIPJEv's formula : p.. Head bluntly conical at its anterior end. No prominent lip. The lips are closed in the specimen depicted in figure 59 a. Labial papillae hort, conical. A crown of 6 bluntly conical more or le s papilliform etae urroun l the head. These setae measure 15,2 % of the corresponding diameter. Cuticle with transverse rows of dots, quite like in Halichoanolaimus. Buccal cavitv with an anterior cylindrical portion, bordered by uniformly cuticularized wall. Its length is 27,7 % of the whole length of the buccal cavil. The ' all of thi ~ portion are structured as in Cobbionema. Follows a row of toothlike corpuscle, these being 6 cusps, which form the prolongations of the longitudinal cuticularized bars, that strengthen the second buccal pace. The e 6 in number apparently function with their cusps a a chewing apparatu. The whole i enveloped by a pharyngeal bulb. Amphids circular, rather small, compo ed of 2 % windings and measuring 22,5 % of the corresponding body diameter. They are situated opposite to the beginning of the posterior buccal cavity. :Sideways, i.e. to the dorsal and ventral side this anterior portion of the buccal cavity is anchored into the pharyngeal bulb by cuticular prong. Tail conical at its basal 42 %, then filiform, rounded at apex, 5,7 anal diameters long. Genus HALICHOANOLAIMUS DE MAN, Halichoanolaimus filicauda FtLIPJEv, (Fig. 63, A-C.) 1 c:j, 1 ~, 1 juv. from Villefranche, between the " Lazareth " and " Anse passable n, grey mud. Depth 50 m. Length: c:f, 2,420 mm; a.= 33,2; ~ = 8,1; y = 7,1. FILIPiEv's formula : M p.. FILIPJEV's : d, length: 3,1 mm; a. = 38; ~ = 10; y = 9. Length : ~ -, 2,28 mm; a. = 28,5; ~ = 8,1; y = 9,5.

109 FREELIVING MARl E 1 EMAS OF THE MEDITERRANEA _ H t FrLIPJEv's formula : i p. v. = 48,5% FILIPJEV'S : l;j?, length : 3,1 mm; a. = 25; ~ = 8; y = 7; V. = 45,5 %. In the dim n ion s there i a clear con formity between FlLIPJEv's data and mine. A for the detail our pccimen an wer rather well to the figures and de cription FrLlPJEV has given. A 62 B FIG Trogolaimus micrampllis n. sp. FIG Halichoanolaimus {ilicauda FrLIPJEV. A: Head end. B: Tail. FIG ~ Desmodora ponlica FILIPJEV. A : Juvenile head end. B : Tail. A : Juvenile head end. B : Female head. C : Male genitale armature and tail. The amphi 1 are in the pre ent specie however more elliptical than in FtLIPJE ' specimen. Head rounded anteriorly with six lips, which bear a hort papilla each. Crown of cephalic setae tran formed into a crown of ten papillae. mphid with 3 X windings, ituatecl opposite to the caudal portion of the buccal cavity; their width 24.2 % of the corre paneling cephalic diameter. Buccal ca ity wide, caliciform, it ve tibulum with vigorously cuticularized wall i followed by a row of toothlike corpuscle and a bundle of caudal rod near the bottom of the buccal cavit.. Iale genital armature consisting of a cur ed pi ulum, lightly attenuated but not knobbed toward the proximal end, pointed di Lally. Chord of the same 1,38 anal diameters. Gubernaculum. hart, plate-like 0,69 time the anal diameter. At least 7 praeanal papillae. Ba al tail portion 12,5 % of the whole tail length. Filiform portion 87,5 % of the arne. Length of tail equal to 6,22 times the anal diameter. 8