Definition.—Thorax with six divergent ribs or radial beams (three primary or perradial alternating with three secondary or interradial).
1. Acanthocorys hexapodia, n. sp.
Cephalis large, ovate, with subregular hexagonal pores, and six strong, conical, simple, divergent horns of the same length. Thorax flat, conical, smooth, with six large triangular basal holes, separated by six strong, prismatic, smooth beams, which are connected only near the distal end by a hexagonal ring of delicate, irregular network. Collar septum with three meshes, separated by the three centripetal prolongations of the three primary ribs.
Dimensions.—Cephalis 0.05 long, 0.04 broad; thorax 0.12 long, 0.24 broad.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
2. Acanthocorys pristipodia, n. sp.
Cephalis large, hemispherical, with irregular, polygonal pores, and numerous (ten to twenty) bristle-shaped, radiating horns, which are conical at the base, and twice as long. Thorax flatly campanulate, thorny, with six strong, serrate or spinulate, divergent, radial ribs, prolonged into six free conical feet of the same length. Meshes of the thorax irregular, polygonal, a corona of six larger ones at the base. Collar septum with four meshes, shaped as in Pl. 56, fig. 6.
Dimensions.—Cephalis 0.04 long, 0.06 broad; thorax 0.08 long, 0.18 broad.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
3. Acanthocorys macropodia, n. sp.
Cephalis small, subspherical, with irregular, roundish pores and numerous small, bristle-shaped horns. Length of the two joints = 1 : 2, breadth = 1 : 6. Thorax sexangular, pyramidal, with six very long and straight, widely divergent feet, which are prismatic and spiny, and three to five times as long as the breadth of the shell. Only the upper third of the six ribs is connected by irregular, roundish network, with six large triangular holes at the base. Collar septum with four meshes which have the same relation to the six ribs as in Sethophormis hexalactis (Pl. 56, fig. 6).
Dimensions.—Cephalis 0.025 diameter, thorax 0.05 long, 0.15 broad.
Habitat.—Central Pacific, Station 271, surface.
4. Acanthocorys bütschlii, Haeckel.
? Clathrocanium ehrenbergii, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. pp. 514, 539, Taf. xxxii. fig. 18, a, b.
Cephalis large, subspherical, with numerous small, circular pores and three to six divergent, slender, apical horns. Thorax flatly conical, smooth, not much larger than the cephalis, with six large, triangular or ovate basal holes between the six ribs. Three of these ribs are primary or perradial, and arise immediately from the collar septum, alternating with three secondary or interradial ribs, which arise more outside. The specimen observed by me exhibited six apical horns, and was more complete than that figured by Bütschli, the six ribs being prolonged over the connecting lattice-girdle into six short, divergent feet.
Dimensions.—Cephalis 0.06 long, 0.06 broad; thorax 0.08 long, 0.1 broad.
Habitat.—Fossil in Barbados.
Definition.—Thorax with nine divergent ribs or radial beams, three of which are primary or perradial, the other six secondary or interradial.
5. Acanthocorys umbellifera, Haeckel.
Arachnocorys umbellifera, Haeckel, 1862, Monogr. d. Radiol., p. 305, Taf. vi. fig. 12.
Cephalis large, ovate, with subregular, circular pores and numerous divergent, simple spines of different lengths. Thorax flatly conical, with nine strong, divergent ribs, which in the distal half are free, in the proximal half connected by numerous transverse beams, forming irregular polygonal meshes. Dorsal face of the thorax armed with scattered ascending spines.
Dimensions.—Cephalis 0.05 long, 0.035 broad; thorax 0.05 long, 0.12 broad.
Habitat.—Mediterranean (Messina); Atlantic, Station 354, surface.
6. Acanthocorys triloba, n. sp.
Cephalis large, campanulate, trilobed, with irregular, roundish pores, numerous spines, and a large pyramidal horn on the top, which is connected by three constricted arches with the base of the horizontal collar beams. From the latter arise as centrifugal prolongations three stout, curved, primary ribs of the flatly vaulted thorax, and each of these gives off at the base two opposite, lateral, secondary ribs. These nine ribs are spiny, and connected by irregular, arachnoidal network.
Dimensions.—Cephalis 0.05 long, 0.07 broad; thorax 0.08 long, 0.18 broad.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
7. Acanthocorys enneapodia, n. sp.
Cephalis large, ovate, with irregular roundish pores, and numerous divergent, ascending spines. Thorax smooth, conical, little larger, with the same network, and nine larger, triangular holes at the base; with nine straight, equally-disposed ribs, which are prolonged into slender feet twice the length. With these latter alternate nine shorter radial spines, arising from the truncate peristome.
Dimensions.—Cephalis 0.05 long, 0.04 broad; thorax 0.05 long, 0.09 broad.
Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.
8. Acanthocorys macroceras, n. sp. (Pl. 97, fig. 12).
Cephalis large, hemispherical, spiny, with regular, circular pores, and a very large, cylindrical, vertical horn five times as long as the whole shell. Thorax spiny, campanulate, with irregular, roundish pores and nine strong, curved ribs, prolonged into nine slender, divergent feet twice the length, which are curved, convex in the proximal half and concave in the distal half.
Dimensions.—Cephalis 0.05 long, 0.08 broad; thorax 0.12 long, 0.2 broad.
Habitat.—South Pacific, Station 298, depth 2225 fathoms.
9. Acanthocorys furcata, n. sp.
Cephalis large, subspherical, spiny, with irregular, roundish pores. Thorax flatly conical, thorny, with irregular, polygonal pores, decreasing in size toward the mouth, and with nine straight divergent ribs, which at the peristome are forked and prolonged into eighteen slender, very long, bristle-shaped feet.
Dimensions.—Cephalis 0.045 diameter, thorax 0.07 long, 0.13 broad.
Habitat.—South Atlantic, Station 323, depth 1900 fathoms.
Definition.—Thorax with a variable number (ten to twenty or more) radial ribs, prolonged into free terminal feet.
10. Acanthocorys dodecaster, n. sp.
Cephalis small, subspherical, with small circular pores and a large conical horn of twice the length, and some accessory spines. Thorax thorny, flatly campanulate, with twelve stout curved ribs, which at the peristome are prolonged into twelve slender, curved feet of twice the length; four of them are centrifugal prolongations of the four cortinar beams separating the four large meshes of the collar septum; eight other ribs are secondary, interpolated in pairs between the former. At the base of the thorax are twelve large triangular holes between the ribs; the other network is irregular, with polygonal meshes.
Dimensions.—Cephalis 0.03 diameter, thorax 0.05 long, 0.12 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
11. Acanthocorys polypodia, n. sp.
Cephalis small, hemispherical, with small, roundish pores and divergent radial spines. Thorax flatly conical, spiny, with twenty to twenty-four divergent, straight ribs, which in the proximal third are separated by the same number of large, triangular meshes, in the middle third connected by irregular network, in the distal third free.
Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.06 long, 0.15 broad.
Habitat.—Central Pacific, Station 273, depth 2350 fathoms.
Definition.—Sethophormida (vel Dicyrtida multiradiata aperta) with numerous radial ribs in the wall of the pyramidal thorax, prolonged into divergent terminal feet. Network double, with an arachnoidal outer mantle around the inner lattice-shell. Cephalis commonly with numerous horns.
The genus Arachnocorys has been derived from the preceding Acanthocorys, by development of numerous external siliceous threads which connect the radial horns of the cephalis with the secondary spines arising from the thoracic ribs. In this way there becomes formed an outer arachnoidal framework, enveloping loosely, like a delicate mantle, the inner primary lattice-shell.
Definition.—Thorax with six divergent ribs or radial beams (three primary or perradial, alternating with three secondary or interradial).
1. Arachnocorys hexaptera, n. sp.
Arachnocorys circumtexta (juv.?), R. Hertwig, 1879, Organism. d. Radiol., p. 79, Taf. viii. fig. 2a.
Cephalis large, subspherical, with irregular, polygonal pores, and numerous bristle-shaped spines twice the length; on the centre of the top a single larger vertical horn. Thorax flatly conical, with six strong and straight widely divergent ribs, which in the proximal half are separated by six large holes, in the distal half connected by a broad ring of irregular network. From each rib arises a perpendicular branch, and these branches are connected together, and with the spines of the cephalis, by arachnoidal network.
Dimensions.—Cephalis 0.04 diameter, thorax 0.08 long, 0.24 broad.
Habitat.—Central Pacific, Station 266; Mediterranean, surface.
2. Arachnocorys discoides, n. sp.
Cephalis small, pyramidal, with irregular, roundish pores and numerous thin spines, on the top a single larger vertical horn. Thorax very flat, nearly discoidal, with six strong and straight ribs, which by communication of few larger and numerous smaller branches form an irregular network with polygonal meshes. From each of the six ribs arise two or three larger, perpendicular branches of half the length, and from the network numerous smaller spines. All these dorsal spines of the shell are connected by a dense arachnoidal wicker-work.
Dimensions.—Cephalis 0.02 diameter, thorax 0.04 long, 0.3 broad.
Habitat.—Central Pacific, Station 271, surface.
Definition.—Thorax with nine divergent ribs or radial beams, three of which are primary or perradial, the other six secondary or interradial. (Sometimes eight or ten occur instead of the nine normal ribs.)
3. Arachnocorys circumtexta, Haeckel.
Arachnocorys circumtexta, Haeckel, 1862, Monogr. d. Radiol., p. 304, Taf. vi. figs. 9-11.
Arachnocorys circumtexta, R. Hertwig, 1879, Organism. d. Radiol., p. 78, Taf. viii. fig. 2.
Cephalis large, subspherical, with numerous roundish pores, and eight to ten slender, conical horns twice the length. Thorax flatly conical, with nine strong, straight, widely divergent, conical feet, each of which bears in the middle of its outer side a perpendicular ascending branch of half the length. These branches and the horns of the cephalis are connected by very thin, parallel, arachnoidal threads. Network of the thorax irregular, with nine larger triangular holes at the base. Collar septum with numerous, irregular, roundish pores.
Dimensions.—Cephalis 0.04 to 0.05 diameter, thorax 0.08 to 0.12 long, 0.15 to 0.25 broad.
Habitat.—Mediterranean (Messina); Atlantic, Stations 347 to 354, surface.
4. Arachnocorys enneaptera, n. sp.
Cephalis large, campanulate, with irregular, polygonal pores, two larger stout pyramidal and numerous slender, bristle-shaped horns. Thorax of the same structure as in the preceding species, only the nine basal holes are of twice the size; the lower network denser (as in Clathrocanium diadema, Pl. 64, fig. 2). Collar septum with numerous, irregular, roundish pores.
Dimensions.—Cephalis 0.05 diameter, thorax 0.12 long, 0.22 broad.
Habitat.—Tropical Atlantic, Station 338, surface.
5. Arachnocorys araneosa, n. sp. (Pl. 56, fig. 11).
Cephalis large, subspherical, with circular, subregular, hexagonally framed pores, and twenty to thirty slender, cylindrical, straight radial spines. Thorax flatly conical, nearly of the same shape as in the two preceding species, but with nine longer ribs, and more irregular, broader network between them. From the middle of each rib arises, nearly horizontally, a strong branch, which is directed outwards. These branches are connected with the spines of the cephalis as well as with the distal half of the ribs, by dense and delicate arachnoidal network, composed of parallel, very thin, siliceous threads (in fig. 11 only partially represented). Collar septum with numerous irregular, roundish pores.
Dimensions.—Cephalis 0.04 diameter, thorax 0.1 long, 0.2 broad.
Habitat.—Central Pacific, Station 270 to 274, surface.
6. Arachnocorys arachnodiscus, n. sp.
Cephalis small, campanulate, conical, with a single very large conical central horn, and numerous smaller accessory spines. Thorax in form and structure similar to that of the three preceding species, but much flatter, being nearly discoidal. The meshes of the network are smaller and more numerous, irregularly polygonal, and the nine basal holes little larger. Collar septum with four large meshes (as in Pl. 60, fig. 6).
Dimensions.—Cephalis 0.25 long, 0.3 broad; thorax 0.04 long, 0.24 broad.
Habitat.—North Pacific, Station 248, surface.
7. Arachnocorys trifida, n. sp.
Cephalis large, campanulate, with irregular, roundish pores and numerous ramified spines; in the centre of the top a larger pyramidal oblique horn of twice the length. Thorax cap-shaped, flatly vaulted, with nine strong convex ribs, prolonged into slender free feet. Three of these nine ribs are the centrifugal prolongations of the three cortinar bars (united in the centre of the collar stricture, separating its three large cortinar meshes); the other six are diverging lateral branches of the former, arising in pairs at both sides of its base. All nine ribs are connected by delicate arachnoidal network with irregular polygonal meshes. From its surface arise thin bristles, and from the base of each main rib a stout, perpendicular branch. All these dorsal spines are connected by irregular, arachnoidal wicker-work, covering thorax and cephalis. (A remarkable primitive species?)
Dimensions.—Cephalis 0.05 long, 0.06 broad; thorax 0.07 long, 0.18 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Definition.—Thorax with a variable number of radial ribs (twelve to twenty or more), prolonged into free terminal feet.
8. Arachnocorys polyptera, n. sp.
Cephalis large, subspherical, with irregular, roundish pores and numerous radial spines. Thorax flatly conical, with numerous radial ribs (twenty to thirty), which are in the distal half free, in the proximal half connected by delicate arachnoidal wicker-work, with polygonal, irregular meshes. From its dorsal face arise numerous radial spines, which are connected together, and with the cephalic spines, by very thin and numerous threads, parallel between every two spines. Similar to Arachnocorys araneosa (Pl. 56, fig. 11), but differing in the structure of the cephalis, and in the greater number of the ribs and spines.
Dimensions.—Cephalis 0.04 diameter, thorax 0.12 long, 0.24 broad.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
Definition.—Sethophormida (vel Dicyrtida multiradiata aperta) without thoracic ribs, with six terminal feet around the mouth. Cephalis free, with an apical horn.
The genus Anthocyrtoma and the four following genera form together the peculiar group of Carpocanida, comprising all those Sethophormida in which the original thoracic ribs are lost, and only the terminal feet remain. Anthocyrtoma is the simplest form of this group, possessing only six terminal feet, three primary perradial, and three alternating, secondary, interradial. It may be directly derived either from Lychnocanium, by interpolation of three interradial feet, or from Hexaspyris by loss of the sagittal ring.
1. Anthocyrtoma serrulata, Haeckel.
Anthocyrtis serrulata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. vi. fig. 7.
Shell pear-shaped, rough, with obliterated collar stricture. Length of the two joints = 1 : 4, breadth = 1 : 3. Cephalis ovate, with very small pores, and a stout conical horn of the same length. Abdomen inflated, truncate, with larger, regular, circular pores, twice as broad as the constricted mouth. Six feet vertical, parallel, serrate, all of the same size, about as long as the cephalis.
Dimensions.—Cephalis 0.06 long, 0.05 broad; thorax 0.2 long, 0.17 broad.
Habitat.—Fossil in Barbados.
2. Anthocyrtoma alterna, n. sp.
Shell pear-shaped, smooth, with distinct collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 6. Cephalis hemispherical, with a slender conical horn of twice the length. Abdomen inflated, subglobular, with regular, circular, hexagonally framed pores, three times as broad as the narrow, constricted mouth. Six feet conical, smooth, somewhat divergent, alternating, of different sizes; the three larger (perradial) half as long as the shell, and twice as long as the three smaller (interradial). (Similar to Anthocyrtis ventricosa.)
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.15 long, 0.18 broad.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
Definition.—Sethophormida (vel Dicyrtida multiradiata aperta) without thoracic ribs, with nine terminal feet around the mouth. Cephalis free, with an apical horn.
The genus Anthocyrtis (in the original definition of Ehrenberg) contained all Dicyrtida without thoracic ribs, with terminal feet. We here restrict the definition to those Sethophormida in which the number of free terminal feet is constantly nine (three primary perradial and three alternate pairs of secondary interradial feet). Anthocyrtis may be derived either directly from Patagospyris by loss of the sagittal ring, or from Lychnocanium by interpolation of three secondary feet.
Definition.—Feet of the peristome-corona divergent, their basal distance less than their terminal distance.
1. Anthocyrtis mespilus, Ehrenberg.
Anthocyrtis mespilus, Ehrenberg, 1854, Taf. xxxvi. fig. 13; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 66, Taf. vi. fig. 4 (not 5).
Shell smooth, with distinct collar stricture. Length of the two joints = 1 : 5, breadth = 2 : 6. Cephalis hemispherical, with a stout pyramidal horn of twice the length. Thorax nearly hemispherical, with regular, circular, quincuncial pores. Mouth scarcely constricted, with nine divergent, triangular, lamellar feet, about as long as the thorax.
Dimensions.—Cephalis 0.012 long, 0.02 broad; thorax 0.05 long, 0.06 broad.
Habitat.—Fossil in Barbados.
2. Anthocyrtis furcata, Ehrenberg.
Anthocyrtis furcata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 2.
Shell smooth, with deep collar stricture. Length of the two joints = 1 : 5, breadth = 2 : 6. Cephalis hemispherical, with a short pyramidal horn of half the length. Thorax hemispherical, with large, irregular, roundish pores. Mouth scarcely constricted, with nine divergent, curved, slender feet, which are about as long as the shell, and forked at the distal end.
Dimensions.—Cephalis 0.01 long, 0.02 broad; thorax 0.05 long, 0.06 broad.
Habitat.—Fossil in Barbados.
3. Anthocyrtis butomus, n. sp.
Shell thorny, with obliterated collar stricture. Length of the two joints = 2 : 6, breadth = 2 : 7. Cephalis ovate, with very small and scarce pores, and a conical horn of the same length. Thorax inflated, pear-shaped, with regular, circular, quincuncial pores. Mouth about half as broad, constricted, with nine divergent, broad, nearly square, lamellar feet, half as long as the thorax (similar to Anthocyrtis serrulata, Ehrenberg, loc. cit., Taf. vi. fig. 7).
Dimensions.—Cephalis 0.05 long, 0.04 broad; thorax 0.12 long, 0.14 broad.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
4. Anthocyrtis ventricosa, Ehrenberg.
Anthocyrtis ventricosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. viii. fig. 1.
Shell thorny, with obliterated collar stricture. Length of the two joints = 1 : 7, breadth = 2 : 7. Cephalis hemispherical, hyaline, without pores, with a slender, conical horn, of about the same length. Thorax inflated, pear-shaped or subspherical, with regular, circular, quincuncial pores. Mouth only one-third as broad, much constricted, with nine divergent, slender, conical feet, about one-fifth as long as the diameter of the shell (partly broken off in Ehrenberg's figure).
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.14 long, 0.14 broad.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms; also fossil in Barbados.
Definition.—Feet of the peristome-corona parallel, vertical; their basal and terminal distances equal.
5. Anthocyrtis ophirensis, Ehrenberg.
Anthocyrtis ophirensis, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 285, Taf. ix. fig. 13.
Shell smooth, with slight collar stricture. Length of the two joints = 2 : 4, breadth = 1 : 5. Cephalis ovate, with irregular, roundish pores, and a pyramidal, excentric, vertical horn of the same length. Thorax campanulate, with delicate network of large, regular, hexagonal pores. Mouth scarcely constricted, with nine parallel, vertical, conical feet, about as long as the cephalis. (In the specimen figured by Ehrenberg only seven feet are represented, two being broken off; two other specimens of this species, captured by Rabbe, exhibited nine regularly disposed feet.)
Dimensions.—Cephalis 0.03 long, 0.02 broad; thorax 0.08 long, 0.1 broad.
Habitat.—Indian Ocean, Zanzibar (Pullen); Madagascar (Rabbe), surface.
6. Anthocyrtis lauranthus, n. sp.
Shell smooth with slight collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis ovate, with large, roundish pores, and a conical horn of twice the length. Thorax inflated, campanulate, with regular, circular, hexagonally framed pores. Mouth two-thirds as broad, little constricted, with nine parallel, vertical, broad, lamellar, triangular feet, half as long as the cephalis.
Dimensions.—Cephalis 0.04 long, 0.03 broad; thorax 0.1 long, 0.12 broad.
Habitat.—Central Pacific, Station 266 to 270, depth 2550 to 2925 fathoms.
7. Anthocyrtis grossularia, Ehrenberg.
Anthocyrtis grossularia, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 6.
Shell spiny, with deep collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 4. Cephalis subspherical, thorny, with a conical horn of the same length. Thorax ovate, spiny, with numerous densely-crowded, subregular, circular pores. Mouth about half as broad, constricted, with nine parallel, vertical, slender, conical feet, about as long as the cephalis.
Dimensions.—Cephalis 0.04 long, 0.05 broad; thorax 0.2 long, 0.18 broad.
Habitat.—Fossil in Barbados.
8. Anthocyrtis subglobosa, n. sp.
Shell spiny, with deep collar stricture. Length of the two joints = 1 : 7, breadth = 1 : 7. Cephalis subspherical, with a conical horn twice the length. Thorax nearly spherical, with small and very numerous, regular, circular pores. Mouth only one-third as broad, constricted, with nine parallel, vertical, square, lamellar feet, about twice as long as the cephalis.
Dimensions.—Cephalis 0.03 long, 0.035 broad; thorax 0.2 long, 0.2 broad.
Habitat.—South Pacific, Station 297, depth 1775 fathoms.
Definition.—Feet of the peristome-corona convergent, their basal distance greater than their terminal distance.
9. Anthocyrtis enneaphylla, n. sp.
Shell smooth, with sharp collar stricture. Length of the two joints = 1 : 6, breadth = 1 : 5. Cephalis subspherical, with a conical horn twice the length, nearly hyaline, with very small and scarce pores. Thorax nearly spherical, with regular, circular, quincuncial pores. Mouth only half as broad, with nine broad, triangular feet, twice as long as the cephalis, and curved inwards, convergent towards the main axis.
Dimensions.—Cephalis 0.02 long, 0.025 broad; thorax 0.11 long, 0.12 broad.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
10. Anthocyrtis ovata, n. sp. (Pl. 62, fig. 13).
Shell smooth, with slight collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 3. Cephalis ovate, with numerous small pores, and an excentric conical horn of the same length. Thorax ovate, with regular, circular, quincuncial pores. Mouth nearly of the same breadth, scarcely constricted, with nine triangular, widely-separated feet, about as long as the cephalis, and convergent towards the main axis.
Dimensions.—Cephalis 0.035 long, 0.03 broad; thorax 0.15 long, 0.1 broad.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
Definition.—Sethophormida (vel Dicyrtida multiradiata aperta) without thoracic ribs, with numerous terminal feet around the mouth (twelve to fifteen or more). Cephalis free, with an apical horn.
The genus Anthocyrtium has been derived from the two preceding genera by further multiplication of the terminal feet, the number of which is at least twelve to fifteen, often twenty or more. It may be that some species have arisen directly from Patagospyris by loss of the sagittal ring.
Definition.—Feet of the peristome-corona divergent, their basal distance less than their terminal distance.
1. Anthocyrtium chrysanthemum, n. sp. (Pl. 62, fig. 14).
Shell smooth, with distinct collar stricture. Length of the two joints = 3 : 7, breadth = 4 : 9. Cephalis hemispherical, with small, circular pores, and a large, straight, cylindro-conical horn, about as long as the shell. Thorax campanulate, hemispherical, with six to eight transverse rows of squarish pores, increasing in size downwards. Mouth little constricted, with twelve to fifteen divergent, curved, slender feet, about as long as the thorax.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.07 long, 0.09 broad.
Habitat.—Central Pacific, Station 270 to 274, depth 2350 to 2925 fathoms.
2. Anthocyrtium centaurea, Haeckel.
Anthocyrtis mespilus, var. major, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. vi. fig. 5.
Shell smooth, with sharp collar stricture. Length of the two joints = 2 : 6, breadth = 3 : 7. Cephalis hemispherical, with irregular, roundish pores, and a very large pyramidal horn, longer than the shell, with contorted edges. Thorax hemispherical, with six to eight transverse rows of regular, circular pores of equal size. Mouth little constricted, with fifteen to twenty divergent, curved, slender feet, about as long as the shell.
Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.06 long, 0.07 broad.
Habitat.—Fossil in Barbados.
3. Anthocyrtium anthemis, n. sp.
Shell papillate, with obliterated collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis hemispherical, with very small and scarce pores, and a conical horn of the same length. Thorax conical, as long as broad, with conical papillæ, and eight to ten transverse rows of roundish pores, gradually increasing in size downwards. Mouth scarcely constricted, with fifteen to twenty divergent, straight, conical feet, half as long as the thorax.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.09 long, 0.09 broad.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
4. Anthocyrtium collare, Haeckel.
Anthocyrtis collaris, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 8.
Shell rough, conical, with obliterated collar stricture. Length of the two joints = 3 : 5, breadth = 4 : 7. Cephalis conical, with a pyramidal horn of the same length, and with two transverse rows of rather oblong, narrow pores. Thorax truncate, conical, in the lower part thorny, with six to eight transverse rows of regular, circular pores, increasing in size downwards.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.05 long, 0.07 broad.
Habitat.—Fossil in Barbados.
5. Anthocyrtium adonis, n. sp. (Pl. 62 fig. 20).
Shell rough, with sharp collar stricture. Length of the two joints = 3 : 10, breadth = 4 : 12. Cephalis subspherical, with very small circular pores, and a very long, straight cylindrical, horn, twice to three times as long as the shell. Thorax inflated, ovate, or subspherical, with small regular, circular, hexagonally-framed pores. Mouth strongly constricted, half as broad as the thorax, with fifteen to twenty divergent, broad, lamellar, rectangular feet, as long as the thorax, and so densely placed that their margins come in contact with one another.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.1 long, 0.12 broad.
Habitat.—Central Pacific, Station 263 to 268, depth 2650 to 3000 fathoms.
6. Anthocyrtium anemone, n. sp.
Shell spiny, with sharp collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 4. Cephalis subspherical, with a conical horn of half the length, hyaline, without pores. Thorax spiny, pear-shaped, inflated, with small and numerous, regular, circular pores. Mouth constricted, half as broad as the thorax, with twelve to fifteen divergent, slender, conical, denticulate feet, half as long as the thorax.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.14 long, 0.12 broad.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms; also fossil in Barbados.
Definition.—Feet of the peristome-corona parallel, vertical; their basal and apical distances equal.
7. Anthocyrtium campanula, n. sp. (Pl. 62, fig. 17).
Shell smooth, with deep collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis spherical, with a conical horn of the same length. Thorax campanulate, thin-walled, with delicate network of regular, hexagonal pores and thin bars. Mouth little constricted, with twenty to twenty-four parallel, vertical, lanceolate feet, about as long as the cephalis.
Dimensions.—Cephalis 0.03 diameter, thorax 0.09 long, 0.1 broad.
Habitat.—South Pacific, Station 302, depth 1450 fathoms.
8. Anthocyrtium reticulatum, Haeckel.
Thyrsocyrtis reticulata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 84, Taf. xii. fig. 10.
Shell rough, with sharp collar stricture. Length of the two joints = 1 : 2, breadth = 1 : 3. Cephalis hemispherical, with a prismatic, denticulate horn of the same length, and small, irregular pores. Thorax campanulate, thorny, thin-walled, with delicate network of irregular, polygonal pores. Mouth little constricted, with twelve (or more) small, parallel, vertical, triangular feet, shorter than the cephalis.
Dimensions.—Cephalis 0.015 long, 0.02 broad; thorax 0.04 long, 0.06 broad.
Habitat.—Fossil in Barbados.
9. Anthocyrtium leptostylum, Haeckel.
Anthocyrtis leptostyla, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. vi. fig. 1.
Shell thorny, with slight collar stricture. Length of the two joints = 1 : 5, breadth = 2 : 4. Cephalis hemispherical, with small, scarce pores and a slender conical horn of the same length. Thorax spiny, with regular, circular, quincuncial pores. Mouth constricted, half as broad, with twelve to eighteen slender, parallel, vertical feet, about as long as the cephalis.
Dimensions.—Cephalis 0.02 long, 0.04 broad; thorax 0.1 long, 0.08 broad.
Habitat.—Central Pacific, Stations 266 to 270, depth 2550 to 2925 fathoms; also fossil in Barbados.
10. Anthocyrtium hispidum, Haeckel.
Anthocyrtis hispida, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 64, Taf. viii. fig. 2.
Anthocyrtis hispida, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 540, Taf. xxxiii. fig. 30.
Shell thorny, with sharp collar stricture. Length of the two joints = 1 : 4, breadth = 2 : 5. Cephalis hemispherical, hyaline, with few very small pores, or without any; with a stout conical horn of twice the length. Thorax spiny, with regular, circular, hexagonally-framed pores (half as broad as the bars between them). Mouth wide open, scarcely constricted, with twelve to fifteen parallel, vertical, broad, lamellar, rectangular feet, reaching nearly the length of the thorax.
Dimensions.—Cephalis 0.02 to 0.03 long, 0.03 to 0.05 broad; thorax 0.07 to 0.09 long, 0.1 to 0.12 broad.
Habitat.—Central Pacific, Stations 263 to 265, depth 2650 to 3000 fathoms; also fossil in Barbados.
11. Anthocyrtium turris, n. sp.
Shell thorny, very similar to Calocyclas turris, Ehrenberg (1875, loc. cit., Taf. xviii. fig. 7), but without fenestrated abdomen. Collar stricture deep. Length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis subspherical, hyaline, without pores, with a stout conical horn of twice the length. Thorax nearly spherical, spiny, with regular, circular, quincuncial pores. Mouth little constricted, with fifteen to twenty parallel, vertical, broad, lamellar, rectangular feet, about as long as the thorax.
Dimensions.—Cephalis 0.03 long, 0.03 broad; thorax 0.1 long, 0.1 broad.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
12. Anthocyrtium doronicum, n. sp. (Pl. 62, fig. 18).
Shell rough, with sharp collar stricture. Length of the two joints = 1 : 5, breadth = 1 : 3. Cephalis hemispherical, with small, circular pores and a stout conical horn of twice the length. Thorax campanulate, subcylindrical, with regular, circular, quincuncial pores, three to four times as broad as the bars. Mouth scarcely constricted, with twenty-four to thirty vertical, nearly parallel, little curved feet, which are about half as long as the shell, broad, lamellar, rectangular, and in close contact with their edges.
Dimensions.—Cephalis 0.025 long, 0.035 broad, thorax 0.12 long, 0.1 broad.
Habitat.—South Pacific, Station 295, depth 1500 fathoms.
Definition.—Feet of the peristome-corona convergent, their basal distance greater than their apical distance.
13. Anthocyrtium pyrum, n. sp. (Pl. 62, fig. 12).
Shell smooth, with obliterated collar stricture. Length of the two joints = 2 : 7, breadth = 3 : 8. Cephalis hemispherical, with a small, bristle-shaped horn of half the length. Thorax inflated, subglobose, with regular, circular, quincuncial pores and thin bars. Mouth constricted, only half as broad, with fifteen to twenty small, triangular, convergent feet, shorter than the cephalis. (In another specimen the feet were twice as long, stronger and more convergent, than in the one figured.)
Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.07 long, 0.8 broad.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
14. Anthocyrtium setosum, Haeckel.