Order Nassellaria

Family Spyridae

	Acanthodesmia viniculata (Muller) (Figure 2C; 15.96) [=Giraffospyris angulata]. Shell composed of a D-shaped sagittal ring, a basal ring and a frontal ring (see Figure 3C). Breadth of frontal ring: ca. 140-180 µm. Ref: Petrushevskaya (1971a), Nigrini and Moore (1979).
	Amphispyris reticulata (Ehrenberg) (Figure 15.95) [=Liriospyris reticulata, ?Tholospyris procera]. From the D-shaped sagittal ring 6 pairs of bars arise which branch and anastomose forming the latticed lateral walls of the shell. Breadth of shell: ca. 230 µm. Ref: Nigrini and Moore (1979).
	Cephalospyris clathrobursa Haeckel (Figure 15.102). Sub-ovoid shell with very delicate, thin wall and very small pores; main lateral spines extend as three-bladed or hollow and perforated feet. Shell height: ca. 200 µm. Ref: Petrushevskaya (1971a).
	Lophospyris pentagona pentagona (Ehrenberg) (Figure 15.97) [=Lophospyris quadriforis, Lophospyris pentagona]. Bars arising from sagittal, basal and frontal rings define large, very regular, polygonal pores. Skeletal bars and spines sharply three-bladed. Breadth of shell: ca 150 µm. Ref: Petrushevskaya (1971a).
	Nephrospyris renilla Haeckel (Figure 15.99) [=Nephrodictyum renilla]. The front and back of the sagittal ring produce branches that fork and anastomose distally; the two sets of lattice plates thus formed are not interconnected laterally. Breadth of shell: ca. 200 µm. Ref: Petrushevskaya (1971a), Goll (1972).
	Phormospyris stabilis scaphipes (Haeckel) (Figure 15.93). Bi-lobulate, sagitally constricted, thin walled skeleton with three conspicuous feet protruding from basal ring. Breadth of shell: ca 80 µm. Ref: Goll (1976).
	Phormospyris stabilis stabilis (Goll) (Figure 15.100). Cephalis thin-walled, bilobulate, separated by a conspicuous annular constriction from the conical thorax. Thorax open or closed. Both segmens with regular, circular pores. Breadth of shell: ca 110 µm. Ref: Goll (1976).
	Tholospyris anthophora (Haeckel) (Figure 15.98). Oval-shaped sagitally constricted skeleton with very heavy bars and circular pores. Shell breadth: ca. 140 µm. Ref: Goll (1969, 1972).
	Tholospyris ramosa (Haeckel) (Figure 15.91) [=Androspyris ramosa]. Shell pear-shaped, sagitally constricted, with a well-developed galea and three feet whose distal ends can be spatulated or forked. Shell height: ca. 180 µm. Ref: Takahashi (1991).
	Tholospyris spp. group (Figure 15.103). Rings of variable size and form very common in most warm water materials; most of these are probably juvenile representatives of various Spyridae.
	Tholospyris tripodiscus Haeckel (Figure 15.92). Generally similar to T. ramosa, but with conspicuously larger pores on both sides of the sagittal ring and at the base of the galea; feet usually unbranched. Shell height: ca. 150 µm. Ref: Petrushevskaya (1971a).
	Triceraspyris antarctica (Haecker) (Figure 15.94) [=Triospyris antarctica, Phormospyris stabilis antarctica]. Heavy bilobulated cephalis with irregularly distributed circular pores and three massive, simple or branched feet at the base; rudiments of thoracic lattice often present between feet. Shell breadth: ca. 100 µm. Ref: Petrushevskaya (1967).
	Zygocircus productus (Hertwig) (Figure 15.101). Pear-shaped or D-shaped, spiny, three-bladed sagittal ring. Major diameter: 90-140 µm. Ref: Petrushevskaya (1971a).

Order Nassellaria

Family Plagoniidae

	Antarctissa spp. group? (Figure 3D, 15.104) [=?Antarctissa strelkovi, ?Antarctissa longa]. Shell outline triangular to oval, cephalis partly submerged into thorax. Shell-wall thick. A. strelkovi (Figure 3D) and A. longa differ from A. denticulata by having thinner and spinier shell-walls. Shell height: 100-160 µm. Ref: Petrushevskaya (1967).
	Arachnocorys circumtexta Haeckel (Figure 15.110). Spherical cephalis provided with numerous spines; those directed upwards are interconnected by a spider web-like lattice of very thin bars; the ones directed toward the base support an incipient thorax formed by a coarser lattice with irregular pores, with several very large pores located in the neck area. Overall shell height: ca. 140 µm. Ref: Petrushevskaya (1971a).
	Callimitra carolotae Haeckel (Figure 15.123). The small, dome-shaped cephalis is provided with very long apical (directed upwards), dorsal and main lateral spines (directed down and sideways) interconnected by a delicate meshwork which forms three basal plates and three lateral plates. Overall shell height: ca. 200 µm. Ref: Haeckel (1887).
	Clathrocanium coarctatum Ehrenberg (Figure 15.114). Cephalis with a large, three-bladed apical horn which may have lateral thread-like, anastomosing pojections. The dorsal and two main lateral spines, directed down and sideways, are joined by narrow lattice plates which form a small thorax. Overall shell height: ca. 100 µm. Ref: Petrushevskaya (1971a).
	Clathrocorys teuscheri Haeckel (Figure 2G; 15.112). Similar to C. coaerctatum, except that the apical, dorsal and main lateral spines are joined by a well-developed lattice. Overall shell height: ca. 150-190 µm. Ref: Petrushevskaya (1971a).
	Helotholus histricosa Jorgensen (Figure 15.113). Spiny, dome-shaped shell. Cephalis merging smoothly with thorax; thorax with large and irregular pores, without defined termination. Maximum shell width: ca. 100-120 µm. Ref: Petrushevskaya (1971a).
	Lampromitra coronata Haeckel (Figure 15.115). Shell in the shape of a Chinese peasant hat. Thorax with subregular circular pores increasing in size slightly towards the base, with a well defined peristome of a row of small pores and minute spines. Shell diameter: ca. 200 µm. Ref: Petrushevskaya (1971a).
	Lampromitra danaes (Haeckel) (Figure 15.116) [=Corocalyptra danaes]. Overall shell-shape similar to L. coronata. Pores on thorax regular, polygonal, strongly increasing in size toward its base. Rim of thorax represented by a very regular row of small, rectangular pores followed inmmediately by one of much larger pores. Shell diameter: ca. 180 µm. Ref: Haeckel (1887), as Clathrocyclas danaes.
	Lampromitra quadricuspis Haeckel (Figure 15.117). Generally similar to L. coronata, except that cephalis is more elongate, pores on thorax are larger and its termination is ragged. Shell diameter: 120-350 µm. Ref: Benson (1966).
	Lampromitra schultzei (Haeckel) (Figure 15.118). Similar to L. coronata, except that pores on thorax are considerably larger and less regular. Peristome with two-three rows of regularly aligned, small, subrectangular pores. Shell diameter: ca. 100 µm. Ref: Boltovskoy and Riedel (1980).
	Lophophaena butschlii (Haeckel) (Figure 15.108). Elongated cephalis, the top of which is usually unfinished, short conical thorax. Overall shell height: ca. 100 µm. Ref: Petrushevskaya (1971a).
	Lophophaena hispida (Ehrenberg) (Figure 3I; 15.109). Cephalis spherical, with very large pores and many long, thin spines. Thorax conical, its pores decreasing in size toward the base; sometimes an incipient abdomen present. Overall shell height: ca. 150 µm. Ref: Petrushevskaya (1971a).
	Neosemantis distephanus (Haeckel) (Figure 15.120). Skeleton composed of an oval or pyriform ring (fused main lateral spines) both poles of which are connected by a third bar (the apical spine); from its base protrudes the dorsal spine. All skeletal elements very spiny. Major ring diameter: 70-80 µm. Ref: Petrushevskaya (1971a).
	Peromelissa phalacra (Haeckel) (Figure 15.107) [=Psilomelissa phalacra, Lithomelissa monoceras]. Oval cephalis whose upper part is unperforated or has very few, very small pores. The dorsal and main lateral spines emerge in the neck region as large, three-bladed appendages. Overall shell height: ca. 100 µm. Ref: Petrushevskaya (1971a).
	Phormacantha hystrix (Jorgensen) (Figure 15.111). Cephalis composed of a loose network of arches defining large, irregular pores. Thorax absent. Shell height: 60-70 µm. Ref: Petrushevskaya (1971a).
	Plagoniidae group (Figure 15.105). Includes many generally similar forms with a latticed cephalis and with or without a rudimentary thorax. The systematics of these sometimes extremely abundant forms is confused, and they are generally ignored in most surveys. They include species cited under a variety of generic names, such as Amphiplecta, Arachnocorallium, Arachnocorys, Ceratocyrtis, Dimelissa, Lophophaena, Lophophaenoma, Micromelissa, Peromelissa, Psilomelissa, etc.
	Pseudocubus obeliscus Haeckel (Figure 15.122). Skeleton represented by the sharply three-bladed edges of a 4-sided, truncated pyramid. Shell height: ca. 40 µm. Ref: Petrushevskaya (1971a).
	Sethophormis aurelia Haeckel (Figure 3F; 15.121). Shell in the form of a Chinese peasant hat; cephalis cupola-shaped; thorax with a very delicate, lace-like meshwork of irregular pores decreasing in size toward the periphery and many radial sinuous ribs. Shell diameter: 150-200 µm. Ref: Petrushevskaya (1971a).
	Sethophormis rotula (Haeckel) (Figure 15.124). Central part of spider web-like skeleton is an hexagonal ring whose vertices support 6 radiating spines; three additional radial spines (dorsal and two main lateral) merge in center of hexagon. All spines produce rather regularly spaced anastomosing lateral branches. Diameter of central hexagon: ca. 40 µm. Ref: Petrushevskaya (1971a).
	Tetraplecta pinigera Haeckel (Figure 15.119). Skeleton reduced to four equidistant three-bladed spines arising from a common central point; spines produce thin lateral braches which can anastomose forming a delicate, irregular web. Length of each spine: 25-30 µm. Ref: Haeckel (1887).
	Trisulcus triacanthus Popofsky (Figure 15.106). Small, sparsely perforated cephalis sitting on top of a conspicuously three-lobulated thorax, lobes are most evident in the uppermost part, disappearing gradually toward the base. Shell height: ca. 60 µm. Ref: Petrushevskaya (1971a).

Order Nassellaria

Family Theoperidae

	Artostrobus annulatus (Bailey) (Figure 15.125). Cephalis cup-shaped, poreless, with a thin apical horn. Thorax cylindrical, with circular (proximally) to subrectangular (distally) pores in transverse rows, increasing in size toward the base. Shell height: up to 160 µm. Ref: Riedel (1958), Petrushevskaya (1967).
	Clathrocyclas cassiopeiae Haeckel (Figure 15.126). Small cephalis with a stout apical horn and many smaller spines. Thorax large, campanulate, with irregular pores. Abdomen short, truncated, with ragged, spiny termination. Shell height: 100-200 µm. Ref: Haeckel (1887).
	Cornutella profunda Ehrenberg (Figure 15.127). Narrow, bilocular conical shell with very small subspherical poreless cephalis with or without apical horn. Pores on thorax circular, increasing in size toward the base. Sell height: 120-230 µm. Ref: Riedel (1958), Nigrini (1967).
	Corocalyptra cervus (Ehrenberg) (Figure 15.128). Cephalis with a large apical horn, often forked distally. Thorax large, campanulate, with regular, polygonal pores in transversal rows increasing in size distally. Abdomen restricted to a narrow brim with several rows of small pores. Shell height: 100-200 µm. Ref: Benson (1966).
	Corocalyptra columba (Haeckel) (Figure 15.132). Subspherical cephalis partly submerged into cupola-shaped thorax, provided with a large apical horn. Thorax with three small wings. Abdomen cylindrical. Shell height: ca. 100-120 µm. Ref: Haeckel (1887), as Pterocorys columba.
	Corocalyptra kruegeri Popofsky (Figure 15.136). Generally similar to C. columba; cephalis larger, thorax and abdomen cylindrical. Shell height: ca. 80 µm. Ref: Popofsky (1913).
	Cycladophora davisiana (Ehrenberg) (Figure 15.131) [=Theocalyptra davisiana, ?Artostrobus jorgenseni]. Shell conical to campanulate. Cephalis subspherical, sparsely perforated, usually with two spines. Thorax conical to cylindrical, with circular (proximally) to quadrate (distally) pores increasing in size toward the base. Abdomen, when present, flared out, wider than thorax, with quadrate pores. Petrushevskaya (1967) described three subspecies of this form, of which C. davisiana (Ehrenberg) davisiana Petrushevskaya (Figure 15.131b) and C. davisiana (Ehr.) cornutoides (Petrushevskaya) (Figure 15.131c) are often used in current literature (the last one is probably synonymous with Artostrobus jorgenseni). Shell height: ca. 100 µm. Ref: Riedel (1958), Petrushevskaya (1967), Bjørklund and Ciesielski (1994).
	Cyrtopera laguncula Haeckel (Figure 3O; 15.151) [=Cyrtolagena laguncula, Stichopera pectinata]. Very typical multisegmented shell with conical outline and clearly marked constrictions; last segment may be open or closed. Shell height: 150-250 µm. Ref: Petrushevskaya (1971a).
	Dictyocephalus papillosus (Ehrenberg) (Figure 15.135) [=Carpocanarium papillosum]. Two-segmented, thick-walled shell. Cephalis spherical. Thorax oval, with circular, usually framed pores, with three short wings, ending in a narrowed, poreless peristome. Shell height: 70-90 µm. Ref: Petrushevskaya (1967).
	Dictyophimus gracilipes Bailey (Figure 15.142) [=Pseudodictyophimus gracilipes, Dictyophimus clevei]. Cephalis partly submerged into thorax, bears a large apical horn. Thorax pyramidal or conical, mouth open or closed, with three conspicuous legs (dorsal and lateral spines). Shell height (without feet): 55-90 µm. Ref: Petrushevskaya (1971a).
	Dictyophimus hirundo (Haeckel) (Figure 15.140) [=Pterocorys hirundo]. Cephalis, globular, sometimes spiny, with a stout, three-bladed apical horn. Thorax truncate-conical to campanulate, spiny, with large circular pores and three ribs which extend into massive, divergent feet. Highly variable species (species group?). Shell height (without feet): 50-100 µm. Riedel (1958), Nigrini and Moore (1979).
	Dictyophimus infabricatus Nigrini (Figure 3Q; 15.143). Similar to D. hirundo, but shell is thinner and pores are larger; cephalis usually wih two horns (apical and vertical spines), feet are smaller. Shell height (without feet): 90-200 µm. Ref: Nigrini and Moore (1979).
	Eucyrtidium acuminatum (Ehrenberg) (Figure 15.137) [=?Eucyrtidium hexagonatum]. Small subspherical cephalis with apical horn. Thorax small, inflated, thick-walled. Abdomen and four-five post-abdominal segments thin-walled, with pores arranged in longitudinal rows. Shell height: 120-200 µm. Eucyrtidium hexagonatum Haeckel is closely related to this species; according to Nigrini (1967) it can be distinguished from E. acuminatum by the sharp change in contour at the lumbar stricture. Ref: Nigrini and Moore (1979).
	Eucyrtidium anomalum (Haeckel) (Figure 15.138). Cephalis spherical, partly submerged into the large, assymetric, conical, thin-walled thorax. Abdomen and two-three postabdominal segments thin-walled, with pores in longitudinal rows. Maximum shell width: 80-100 m. Ref: Petrushevskaya (1971a).
	Eucyrtidium hexastichum (Haeckel) (Figure 15.139). Cylindrical or cnical shell with up to 9-10 segments, thin-walled, with pores arranged in transversal rows. Maximum shell width: 65-80 µm. Ref: Petrushevskaya (1971a).
	Lipmanella bombus (Haeckel) (Figure 15.133) [=Dictyoceras cf. pyramidale]. Very characteristic thorax where the dorsal and main lateral spines, which project down and sideways, are surmounted by latticed keels; these keels define the three slightly concave sides of the pyramidal thorax. Maximum shell width: 80-150 µm. Ref: Benson (1966), Petrushevskaya (1971a).
	Lipmanella dictyoceras (Haeckel) (Figure 3R, 15.134) [=Lipmanella virchowii, Dictyoceras virchowii, Dictyoceras neglectum]. Cephalis large, hemispherical, wih a conspicuous apical horn. Thorax thin-walled, conical-inflated, with three wings (dorsal and main lateral spines). Abdomen absent or rudimentary. Shell height: 90-130 µm. Ref: Petrushevskaya (1971a).
	Litharachnium tentorium Haeckel (Figure 15.148). Two-segmented, very characteristic shell. Cephalis very small, spherical, hyaline. Thorax conical proximally, flaring rapidly outward distally and, in complete specimens, ending in a gently curved brim. Diameter of fully-grown shells: up to 1 mm. Ref: Benson (1966), Petrushevskaya (1971a).
	Lithopera bacca Ehrenberg (Figure 15.129). Spherical, often rough cephalis with an eccentrically located apical horn partly submerged into an oval thorax with closed mouth. Pores on thorax regularly arranged. Shell height: 120-140 µm. Ref: Benson (1966).
	Lithostrobus hexagonalis Haeckel (Figure 15.141). Multisegmented, subconical shell with 5-9 joints with well marked strictures and angular shoulders. Pores very regular, subpolygonal, in transverse rows. Shell height: 120-300 µm. Ref: Benson (1966).
	Perypiramis circumtexta Haeckel (Figure 15.130) [=?Plectopyramis dodecomma]. Cephalis very small, ovate, hyaline. Thorax large, conical, with ca. 10 well defined longitudinal rows of subquadrate pores rapidly increasing in size toward the base. Pores are usually not aligned transversely. The form described as Plectopyramis dodecomma Haeckel differs from P. circumtexta in that pores are aligned transversely as well as longitudally. Bathropyramis woodringi is also similar to the above, but has thicker longitudinal bars and aligned horizontal (transverse) bars. Shell height: 100-300 µm. Ref: Riedel (1958), Nigrini and Moore (1979).
	Pterocanium elegans (Haeckel) (Figure 15.147). Cephalis relatively small, with two large horns (apical and vertical spines). Thorax a large, thin-walled, three-sided pyramid with small, very regular subcircular pores and thin bars; edges of pyramid continue as three strong three-bladed legs. Abdomen cylindrical, may be rudimentary. Shell height (without horns): 180-260 µm. Ref: Benson (1966), as Pterocanium cf. elegans.
	Pterocanium praetextum (Ehrenberg) group? (Figure 15.146). Similar to P. trilobum, from which it sometimes is difficult to separate; differs by having a thorax with more pronounced, angular shoulders, and often a better developed abdomen. Shell height (without horn and feet): 100-120 µm. Ref: Petrushevskaya (1971a).
	Pterocanium trilobum (Haeckel) (Figure 3H; 15.145). Cephalis relatively small, with a stout apical horn. Thorax an inflated tetrahedron with regularly arranged circular pores, with three ribs extending into stout, three-bladed, slightly curved feet. Abdomen, when present, rudimentary. Shell height (without horn and feet): 100-120 µm. Ref: Nigrini and Moore (1979).
	Pterocyrtidium dogieli Petrushevskaya (Figure 15.144) [=Sethoconus dogieli]. Cephalis hemispherical, almost poreless, thick-walled. Thorax cylindrical, thorny, with very large, irregular, subcircular pores. Shell height: ca. 140 µm. Ref: Petrushevskaya (1971a).
	Sethoconus anthocyrtis Haeckel (Figure 15.150) [=Conarachnium polyacanthum, Lophocorys polyacantha]. Cephalis spherical, spiny. Thorax clearly differentiated from cephalis, very large, conical, spiny, with large, regular, subpolygonal pores approximately in longitudinal rows; termination ragged. Shell height: 200-300 µm. Ref: Haeckel (1887).
	Theopilium tricostatum (Haeckel) (Figure 15.149) [=?Theocalyptra gegenbauri]. Chinese peasant hat-like shell with a small cephalis. Thorax widely open, with small, regularly arranged pores, circular proximally and becoming larger and more polygonal distally, with three conspicuous symmetrical ribs (dorsal and main lateral spines). Abdominal brim flat, with 5-8 rows of very regular, quadrangular pores. Shell diameter: 130-300 µm. Ref: Haeckel (1887), Benson (1966).

Order Nassellaria

Family Carpocaniidae

Carpocanium spp. (Figure 3E, 15.170) [=Carpocanistrum spp.]. Shell outline subspherical to oval. Cephalis indistingishable from thorax, included within its upper part. Peristome poreless, smooth or provided with teeth. Height of shell: 80-130 µm. Ref: Nigrini and Moore (1979).

Order Nassellaria

Family Pterocorythidae

	Anthocyrtidium ophirense (Ehrenberg) (Figure 15.152). Cephalis elongate with a large three-bladed apical horn. Thorax campanulate, with circular, regular pores arranged hexagonally; peristome distinct, constricted, may bear terminal teeth. Abdomen absent. Maximum breadth of thorax: 90-140 µm. Ref: Nigrini and Moore (1979).
	Anthocyrtidium zanguebaricum (Ehrenberg) (Figure 15.153). Similar to A. ophirense, but apical horn is smaller, thorax less campanulate, narrower, and terminal teeth smaller or absent. Maximum breadth of thorax: 60-80 µm. Ref: Nigrini and Moore (1979).
	Lamprocyclas maritalis group? Haeckel (Figure 3P; 15.158). Massive shell; cephalis oval, with a large apical horn. Thorax cupola-shaped, with regular, circular, framed pores. Abdomen separated by a conspicuous lumbar stricture, inflated, with larger, regularly arranged, framed pores, usually with a well-defined poreless perstome with teeth. L. m. maritalis Haeckel differs from L. m. Haeckel polypora Nigrini in having a less inflated abdomen. Maximum breadth of abdomen: 100-140 µm. Ref: Nigrini and Moore (1979).
	Lamprocyrtis hannai Campbell and Clark (Figure 15.154) [=Lamprocyrtis hannai, Lamprocyclas junonis]. Cephalis elongate, with a large three-bladed apical horn. Thorax campanulate, thick-walled, with subregular, circular pores. Abdomen truncate-conical, with large, subregular, circular pores and usually with terminal and/or subterminal teeth. Maximum breadth of abdomen: 90-150 µm. Ref: Nigrini and Moore (1979).
	Lamprocyrtis nigriniae (Caulet) (Figure 15.157) [=Conarachnium nigriniae, Lamprocyrtis haysi]. Cephalis elongated, usually open poximally, with a large three-bladed horn. Thorax campanulate, thin-walled, with large, subregular, circular pores increasing in size distally; peristome absent or weakly developed. No abdomen. Maximum breadth of thorax: ca. 90 µm. Ref: Nigrini and Moore (1979).
	Pterocorys hertwigii (Haeckel) (Figure 15.155) [=Theoconus hertwigii, Phormocyrtis fatuosa]. Cephalis oval, horned. Thorax campanulate. Abdomen conical, with ragged termination. Thorax and abdomen thin-walled, with regular circular pores in longitudinal rows, with several continuous or interrupted longitudinal poreless ribs. Total shell height (excluding horn): 120-200 µm. Ref: Caulet and Nigrini (1988).
	Pterocorys minythorax (Nigrini) (Figure 15.156) [=Theoconus minythorax]. Cephalis subspherical, horned. Thorax small, campanulate. Abdomen comparatively large, cylindrical, slightly flared, with ragged termination. Pores on thorax and abdomen regular, circular. Total shell height (excluding horn): 120-200 µm. Ref: Caulet and Nigrini (1988).
	Pterocorys zancleus (Muller) (Figure 15.159) [=Theoconus zancleus, ?Pterocorys sabae, ?Pterocorys campanula]. Cephalis subcircular, horned. Thorax a truncated cone, with three small wings. Abdomen cylindrical or conical, slightly flared. Total shell height (exluding horn): 100-230 µm. Ref: Benson (1966), Petrushevskaya (1971a).
	Pteroscenium pinnatum Haeckel (Figure 15.162) [=Verticillata hexacantha]. Campanulate one-segmented shell with delicate lattice of small, circular pores. Top of cephalis extends into a large, proximally perforated, three-bladed horn; base is prolonged into three stout, perforated, slightly bent feet. Total shell height (including horn and feet): 220-280 µm. Cephalis does not seem to be agree with the family-level diagnosis; probably a plagoniid. Ref: Haeckel (1887), Benson (1966).
	Stichopilium bicorne Haeckel (Figure 15.161). Cephalis cap-shaped, with two stout, three-bladed horns. Thorax pyramidal (proximally) to cylindrical (distally), with three conspicuous wings. One or two cylindrical post-thoracic segments. Thorax and subsequent joints with small, circular, regularly arranged pores. Although this species has traditionally been ascribed to the Pterocorythidae, its cephalis does not seem to be divided into lobes, and is therefore probably a theoperid. Ref: Haeckel (1887), Benson (1966).
	Theocorythium trachelium (Ehrenberg) (Figure 15.160) [=Calocyclas amicae, Lamprocyclas trachelius, Lamprocyclas cranoides]. Cephalis spherical, with a prominent, three-bladed apical horn. Thorax campanulate, inflated. Abdomen cylindrical, with a slight medial constriction; peristome diffentiated, toothed. Pores on post-cephalic segments circular, regularly arranged. Total shell height (without horn): 150-200 µm. Ref: Petrushevskaya (1971a).

Order Nassellaria

Family Artostrobiidae

	Botryostrobus aquilonaris (Bailey) (Figure 15.164) [=Lithocampe aquilonaris]. Very thick-walled, spindle-shaped skeleton with 6 poorly defined joints, of which the fourth is the broadest. Poreless peristome usually present. Shell height: 100-150 µm. Ref: Nigrini and Moore (1979).
	Botryostrobus auritus/australis (Ehrenberg) (Figure 3J; 15.168). [=Lithostrobus seriatus]. Multisegmented cylindrical shell of variable wall-thickness. Cephalis subspherical, apical tube and apical spine usually visible. Thorax and post-thoracic segments inflated, separated by conspicuous strictures, with three-five transverse rows of pores. Shell height: 110-200 µm. Ref: Boltovskoy and Vrba (1989).
	Phormostichoartus corbula (Harting) (Figure 15.163) [=Lithocampe multiseriata, Siphocampe corbula]. Four-segmented shells. Cephalis and thorax fused, thick-walled. Abdomen short, cylindrical. Last segment usually three-four times longer than previous, both with circular pores arranged regularly in transverse rows. Shell height: 130-170 µm. Ref: Nigrini and Moore (1979).
	Siphocampe arachnea (Ehrenberg) (Figure 15.167) [=Lithomitra arachnea]. Cylindrical shell with three-eight joints, with four transverse rows of small, circular pores on the thorax and one on each subsequent segment. Surface covered with a typical net of irregular longitudinal and transverse ridges. Shell height: ca. 60-90 µm. Ref: Petrushevskaya (1967).
	Siphocampe lineata (Ehrenberg) (Figure 15.169) [=Lithomitra lineata, Lithomitra nodosaria, Siphocampe nodosaria]. Very similar to S. arachnea, except that surface ornamentation is restricted to longitudinal, sinuous ridges. Shell height: ca. 80-110 µm. Ref: Petrushevskaya (1967).
	Spirocyrtis scalaris Haeckel group? (Figure 15.166) [=Spyrocyrtis scalaris/cornutella]. Thin-walled shell composed of up to 8 joints with a typically angular outline increasing step-wise in width toward the base. Pores on post-thoracic segments quadrangular, arranged in very regular transverse rows. Shell height: 100-200 µm. Ref: Nigrini (1967), Petrushevskaya (1971a).
	Tricolocampe cylindrica Haeckel (Figure 15.165) [=Siphocampium cylindrica]. Cephalis and thorax fused, separated from rest of shell by a conspicuous lumbar constriction. Abdomen and postabdominal section cylindrical to spindle-shaped, without external constrictions, with several very regularly arranged transverse rows of small, circular pores. Shell height: ca. 90 µm. Ref: Benson (1966), Pterushevskaya (1971a).

Order Nassellaria

Family Cannobotryidae

	Acrobotrys spp. (Figure 3M, 3N; 15.171). Several poorly defined Cannobotryidae of variable construction (e.g., Acrobotrys sp. A, B, C in Petrushevskaya 1965; Acrobotrys cf. disolenia in Benson 1966; Acrobotrys sp. A and B, Cannobotryid sp. A in Boltovskoy and Riedel 1987; etc.).
	Botryocephalina armata Petrushevskaya (Figure 15.173). Main part of cephalis represented by two laterally fused hemispherical chambers of almost equal size (cephalic and antecephalic); with a long apical spine. Thorax cylindrical, its distal section can be poreless. Shell height: ca. 50 µm. Ref: Petrushevskaya (1965).
	Botryocyrtis scutum (Harting) (Figure 15.172) [=?Botryocyrtis caput-serpentis, ?Botryocyrtis quinaria]. Large, multilobed cephalis. Thorax very short, cylindrical. Abdomen longer. Sometimes one post-abdominal segment. Entire shell, and especially its upper section, enclosed in a thick, spongy mantle. Shell height: 80-130 µm. Ref: Nigrini and Moore (1979).
	Botryopyle dictyocephalus Haeckel (Figure 15.174). Cephalis chiefly composed of a large, ovoid, thin-walled antecephalic chamber, and a much smaller, spherical, thick-walled eucephalic chamber. Cervical constriction absent. Thorax cylindrical, with ragged temination or distally narrowing into a short, poreless tube. Shell height: ca. 100 µm. Ref: Petrushevskaya (1965).
	Centrobotrys thermophila Petrushevskaya (Figure 15.175). Shell is a laterally compressed, very thin walled, pored cone, within which the spherical, thick-walled eucephalic chamber is enclosed. Shell height: ca. 100 µm. Ref: Petrushevskaya (1965).
	Saccospyris antarctica Haecker (Figure 15.176). Cephalis tri-lobulated, with the cephalic and antecephalic chambers much larger than the postcephalic one, and approximately equal in size. Thorax cylindrical, with a closed mouth in fully-grown specimens. Shell thick-walled, surface rough. Shell height: 110-160 µm. Ref. : Petrushevskaya (1965).