The genus Theophormis commences the series of the Theophormida, or the multiradiate Podocyrtida, as their oldest and simplest form. The three-jointed shell is flat, campanulate or hat-shaped, and pierced by four or more radial ribs, four of which are primary or perradial, the others secondary or interradial. Theophormis may be derived from the similar Sethophormis by development of a lumbar constriction, and a third joint or abdomen.
1. Theophormis callipilium, n. sp. (Pl. 70, figs. 1-3).
Shell flat, hat-shaped, with two sharp annular strictures. Cephalis large, flatly cap-shaped, with small, irregular, square meshes (fig. 3). The collar septum (fig. 2) is composed (as in the following species) of four crossed, thin, horizontal beams, each of which is inserted at the collar stricture by a three forked branch. From the centre of the collar stricture (in the common nodal point of the four beams) there arises a vertical, axial rod, which is inserted at the flat top of the cephalis by five branches (one central and four lateral). Length of the three joints = 1 : 3 : 2, breadth = 2 : 6 : 11. Thorax flat, campanulate, with four primary perradial ribs (prolongations of the four cortinar beams), and numerous (twenty to thirty) interpolated secondary ribs; four of these are in interradial (midway between the four primary ribs), and bisect the four large, semicircular, perradial meshes at the base of the thorax. Network of the thorax and abdomen subregular, with hexagonal meshes and thin bars. Abdomen flatly expanded, somewhat curved, like the brim of a hat, half as broad in the anterior (frontal) part as in the posterior (occipital) part, which is about as broad as the radius of the thorax. The twenty to thirty radial ribs of the abdomen are prolongations of the thoracic ribs, and are somewhat prominent at the margin of the peristome, which appears therefore elegantly indented.
Dimensions.—Length of the three joints, a 0.02 to 0.03, b 0.06 to 0.08, c 0.03 to 0.06; breadth, a 0.05 to 0.08, b 0.2 to 0.3, c 0.4 to 0.5.
Habitat.—Central Pacific, Station 271, surface.
2. Theophormis medusa, n. sp.
Shell flatly campanulate, with two distinct, annular strictures. Length of the three joints = 1 : 2 : 1, breadth = 2 : 5 : 8. Cephalis large, hemispherical. Thorax flatly conical, with four crossed ribs, opposite in pairs in two meridional planes, perpendicular one to another, and prolonged into the flat, nearly discoidal abdomen, which is half as broad as the thorax. The wall of the abdomen is pierced by eight radial ribs; four secondary ribs being interpolated between the four primary. Network of the entire shell very delicate, with regular, hexagonal meshes, and very thin bars. Peristome circular, not dentate.
Dimensions.—Length of the three joints, a 0.03, b 0.07, c 0.04; breadth, a 0.06, b 0.16, c 0.24.
Habitat.—Central Pacific, Station 266, surface.
3. Theophormis cruciata, n. sp.
Shell flat, campanulate, with two distinct annular strictures. Cephalis flat, cap-shaped, with irregular, square meshes. Thorax flat, conical, with hexagonal meshes. Abdomen flatly expanded, of half the breadth, with larger hexagonal meshes. Thorax and abdomen pierced by four stout radial ribs, lying opposite in pairs in two diameters, perpendicular one to another. No secondary or interradial ribs are interpolated between the four primary. Mouth truncate, circular.
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.04; breadth, a 0.05, b 0.18, c 0.25.
Habitat.—Central Pacific, Station 274, surface.
4. Theophormis senaria, n. sp.
Shell flat, hat-shaped, similar to Theophormis callipilium (Pl. 70, figs. 1-3), but with a different number and arrangement of the piercing radial ribs. The cephalis and its collar septum exhibit the same formation as in Sethophormis hexalactis, described above (p. 1245, Pl. 56, fig. 6.) The caudal and sternal ribs, which are opposed in the sagittal plane, are simple, whilst the two lateral ribs are forked. In the flat abdomen there are six secondary or interradial ribs, interpolated between the six primary or perradial ribs of the thorax. Delicate network with regular, hexagonal meshes.
Dimensions.—Length of the three joints, a 0.035, b 0.075, c 0.025; breadth, a 0.07, b 0.2, c 0.3.
Habitat.—Central Pacific, Station 272, surface.
Definition.—Theophormida (vel Tricyrtida multiradiata aperta) with numerous radial ribs enclosed in the wall of the thorax, and of the ovate or cylindrical abdomen; mouth of the latter constricted.
The genus Phormocyrtis differs from the preceding Theophormis in the ovate or cylindrical form of the abdomen, the mouth of which is more or less constricted. The former exhibits, therefore, the same relation to the latter that Sethamphora bears to Sethophormis among the Dicyrtida. Phormocyrtis may be derived directly either from Sethamphora by development of an abdomen, or from Pterocorys or Theopilium by multiplication of the three radial ribs.
1. Phormocyrtis carinata, n. sp.
Shell ovate, with two slight strictures. Length of the three joints = 1 : 2 : 3, breadth = 1 : 3 : 4. Cephalis hemispherical, with a stout pyramidal horn of twice the length, and few very small pores. Pores in the campanulate thorax and the inflated abdomen regular, circular, small, and numerous. Six stout prominent ribs, beginning from the collar stricture, arise along the thorax and abdomen, and reach the constricted mouth, which is half as broad as the abdomen. (This species is very similar to Pterocorys carinata, from which it differs in the six complete radial ribs of the shell-wall.)
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.09; breadth, a 0.03, b 0.09, c 0.12.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
2. Phormocyrtis fastosa, Haeckel.
Eucyrtidium fastosum, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 291, Taf. ix. fig. 19.
Shell ovate, with two distinct strictures. Length of the three joints = 1 : 3 : 3, breadth = 1 : 5 : 6. Cephalis ovate, with a stout pyramidal horn of the same length, and numerous rather large pores. Pores in the campanulate thorax and the inflated abdomen much smaller, very numerous, regular, hexagonal. Along these two joints arise nine delicate, divergent ribs; these extend almost to the wide mouth, which is slightly constricted.
Dimensions.—Length of the three joints, a 0.03, b 0.09, c 0.08; breadth, a 0.02, b 0.1, c 0.12.
Habitat.—Indian Ocean (Zanzibar), depth 2200 fathoms, Pullen.
3. Phormocyrtis costata, n. sp. (Pl. 69, fig. 6).
Shell smooth, with sharp collar, but indistinct lumbar stricture. Length of the three joints = 2 : 5 : 5, breadth = 2 : 6 : 6. Cephalis conical, with a stout pyramidal horn of twice the length. Thorax and abdomen together nearly cylindrical, constricted towards both poles, with thirty to forty longitudinal ribs, which are nearly parallel, vertical in the middle part, and convergent towards both poles; alternate with the same number of longitudinal rows of regular, circular pores. Mouth with a broad, hyaline, only slightly constricted peristome.
Dimensions.—Length of the three joints, a 0.04, b 0.1, c 0.1; breadth, a 0.04, b 0.12, c 0.12.
Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
4. Phormocyrtis embolum, Haeckel.
Eucyrtidium embolum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. x. fig. 5.
Shell smooth, with sharp collar, but indistinct lumbar stricture. Length of the three joints = 3 : 7 : 10, breadth = 3 : 9 : 7. Cephalis subspherical, with a pyramidal horn of the same length. Thorax campanulate; abdomen inversely truncate, conical; both with sixteen to twenty longitudinal ribs, and alternate longitudinal rows of small circular pores, converging towards the two poles. Mouth truncate, with broad hyaline peristome.
Dimensions.—Length of the three joints, a 0.03, b 0.07, c 0.1; breadth, a 0.03, b 0.09, c 0.07.
Habitat.—Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms; fossil in Barbados.
5. Phormocyrtis quadrata, n. sp.
Shell ovate, papillate, with two slight strictures. Length of the three joints = 2 : 3 : 13, breadth = 4 : 6 : 11. Cephalis hemispherical, small, with two divergent, pyramidal horns of twice the length. Along the hemispherical thorax and the ovate inflated abdomen run twenty-four to thirty curved ribs, converging towards the two poles, and alternate with the same number of longitudinal rows of circular, regular pores, disposed in ten to twelve transverse rows. Each pore with a square, elevated frame. Mouth constricted, only one-third as broad as the thorax.
Dimensions.—Length of the three joints, a 0.02, b 0.03, c 0.13; breadth, a 0.04, b 0.06, c 0.11.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
6. Phormocyrtis longicornis, n. sp. (Pl. 69, fig. 15).
Theocorys longicornis, Haeckel, 1881, Prodromus et Atlas, loc. cit.
Shell slender, ovate, rough, with two slight strictures. Length of the three joints = 3 : 8 : 12, breadth = 4 : 10 : 11. Cephalis hemispherical, with a very large, cylindrical horn, about as long as the shell. Thorax hemispherical, with regular, circular, hexagonally-framed pores. Abdomen subcylindrical, with twenty to twenty-four nearly parallel undulate ribs, and alternate longitudinal rows of regular, circular pores. Mouth constricted, circular, about half as broad as the thorax.
Dimensions.—Length of the three joints, a 0.03, b 0.08, c 0.12; breadth, a 0.04, b 0.1, c 0.11.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados.
Definition.—Theophormida (vel Tricyrtida multiradiata aperta) with numerous radial ribs in the abdomen, which are prolonged over the mouth into free feet.
The genus Alacorys and the following Cycladophora differ from the preceding two genera in the formation of the radial ribs, which arise from the lumbar stricture, and lie in the wall of the abdomen, but are absent on the thorax. The shell is usually large, more or less pyramidal or conical, with a wide open terminal mouth. The latter is in Cycladophora simply truncate, whilst in Alacorys it is surrounded by from four to twelve or more terminal feet, prolongations of the abdominal ribs. According to the different number of these (four, five, six, or more) some subgenera may be distinguished, as Tetralacorys, Pentalacorys, Hexalacorys, &c.
Definition.—Peristome armed with four feet, opposite in two meridian planes, which are perpendicular to one another.
1. Alacorys lutheri, n. sp. (Pl. 65, fig. 4).
Shell papillate, with distinct collar stricture. Length of the three joints = 3 : 6 : 6, breadth = 3 : 8 : 10. Cephalis subspherical, with a pyramidal horn of the same length. Thorax tuberculate, nearly hemispherical, with circular pores of very different sizes. From the margin of its wide open mouth descend four stout perradial ribs, which are forked at the distal end, and by communication of their fork-branches form the four large, pentagonal holes of the abdomen. From the middle of the lower margin of the holes descend four parallel, vertical, slender feet, about as long as the shell. This species is dedicated to the memory of the great Reformer, Martin Luther.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.06; breadth, a 0.03, b 0.08, c 0.1.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
2. Alacorys tetracantha, Haeckel.
Podocyrtis tetracantha, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiii. fig. 2.
? Podocyrtis parvipes, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xiv. fig. 5.
Shell rough, with distinct collar stricture. Length of the three joints = 1 : 3 : 5, breadth = 1 : 4 : 6. Cephalis subspherical, with a rudimentary conical horn. Thorax campanulate, with irregular, roundish pores of different sizes. Abdomen inflated, with a small number of very large irregular holes, intermingled with smaller roundish holes. From the margin of the wide open mouth descend, nearly vertically, four strong vertical feet, which are about as long as the shell, and slightly curved, with convex outlines. Podocyrtis parvipes of Ehrenberg seems to be only a mutilated specimen of this species.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.09; breadth, a 0.03, b 0.08, c 0.13.
Habitat.—Fossil in Barbados.
Definition.—Peristome armed with five feet, one of which is odd and occipital, the other four paired and lateral.
3. Alacorys pentacantha, Haeckel.
Podocyrtis pentacantha, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 82, Taf. xvii. fig. 1.
Shell rough, with slight collar stricture. Length of the three joints = 1 : 2 : 3, breadth = 1 : 4 : 6. Cephalis subspherical, with a rudimentary conical horn. Thorax campanulate, with subregular, circular, quincuncial pores. Abdomen wider, campanulate, with a small number of very large and irregular, roundish holes. From the peristome descend five stout conical feet, which are slightly curved and divergent, nearly as long as the shell.
Dimensions.—Length of the three joints, a 0.02, b 0.05, c 0.06; breadth, a 0.025, b 0.08, c 0.11.
Habitat.—Fossil in Barbados.
4. Alacorys bismarckii, n. sp. (Pl. 65, fig. 3).
Shell spiny, with distinct collar stricture. Length of the three joints = 1 : 4 : 5, breadth = 2 : 7 : 10. Cephalis hemispherical, with a very stout, dimpled, conical horn of the same length. Thorax campanulate, spiny, with regular, circular pores. Abdomen wider, campanulate, with larger conical spines, and a small number of irregular, roundish, very large holes. From the peristome descend, nearly vertically, five very large cylindrical feet, nearly twice as long as the shell; they are S-shaped, curved, spinulate in the distal half, and armed at the proximal base with two stout conical spines, the smaller of which is directed inwards, the larger curved upwards. Dedicated to Prince Otto von Bismarck, the Reconstructor of the German Empire.
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.1; breadth, a 0.04, b 0.14, c 0.2.
Habitat.—Western Tropical Pacific (north of New Guinea), Station 220, depth 1100 fathoms.
Definition.—Peristome armed with six feet, three of which are primary or perradial (Podocyrtis), the three other alternate, secondary or interradial.
5. Alacorys friderici, n. sp. (Pl. 65, fig. 1).
Shell conical, rough, with sharp collar stricture. Cephalis subspherical, with a large, oblique, prismatic horn, twice the length. Thorax campanulate, with regular, circular pores (six to eight in its length). Abdomen wider, campanulate, with a small number of very large pores (three to four in the course of its length). Peristome with six very large divergent feet, which are about as long as the shell, cylindrical, irregularly curved. The specimen figured was observed living, with expanded pseudopodia. The central capsule exhibited four large pear-shaped lobes, filling up the shell-cavity; each contained an oil-globule in the thoracic part. The undivided cephalic part of the capsule enclosed a nucleus, from which four lobes protruded through the four collar pores into the thorax. Dedicated to Frederick the Great, the Royal Philosopher of Potsdam.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.08; breadth, a 0.04, b 0.09, c 0.14.
Habitat.—North Atlantic, Canary Islands, Lanzerote (Haeckel), surface.
6. Alacorys guilelmi, n. sp. (Pl. 65, fig. 2).
Shell thorny, with distinct collar stricture. Length of the three joints = 1 : 3 : 4, breadth = 2 : 5 : 8. Cephalis hemispherical, with a rudimentary conical horn. Thorax hemispherical, spiny, with regular, circular pores. Abdomen wider, campanulate, papillate, with a small number of very large circular holes. Peristome with six diverging feet, which are about as long as the shell, at the base conical, thickened, and at the distal end curved inwards, with a spinulate knob. Dedicated to the German Emperor, Wilhelm.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.08; breadth, a 0.03, b 0.1, c 0.16.
Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.
7. Alacorys hexacantha, n. sp.
Shell thorny, with slight collar stricture. Length of the three joints = 2 : 5 : 7, breadth = 4 : 10 : 14. Cephalis flat, cap-shaped, with a rudimentary conical horn. Thorax campanulate, with regular, circular pores. Abdomen wider, campanulate, with a small number of very large polygonal pores. Peristome with six large divergent feet, which are longer than the shell, cylindrical, and slightly curved, in the proximal half convex, in the distal half concave.
Dimensions.—Length of the three joints, a 0.02, b 0.05, c 0.07; breadth, a 0.04, b 0.1, c 0.14.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
8. Alacorys hexapleura, n. sp.
Shell spiny, with distinct collar stricture. Length of the three joints = 2 : 10 : 8, breadth = 3 : 11 : 10. Cephalis hemispherical, large, hyaline, and thick-walled, with a very stout, conical horn of the same length. Thorax pear-shaped, with numerous, regular, circular pores and conical spines, the size of which increases gradually towards the deep, lumbar stricture. Abdomen truncate, conical, with irregular, roundish pores, and six very strong, straight, divergent ribs, prolonged into six short, conical feet.
Dimensions.—Length of the three joints, a 0.04, b 0.2, c 0.16; breadth, a 0.06, b 0.22, c 0.2.
Habitat.—Fossil in Barbados.
Definition.—Peristome armed with eight feet, four of which are primary or perradial (corresponding to those of Tetralacorys), the other four alternate, secondary, or interradial.
9. Alacorys aculeata, Haeckel.
Podocyrtis aculeata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xiii. fig. 3.
Podocyrtis aculeata, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 540, Taf. xxxiii. fig. 34.
Shell spiny, with deep collar stricture. Length of the three joints = 2 : 5 : 8, breadth = 2 : 7 : 10. Cephalis subspherical, with a slender, conical horn of twice the length. Thorax campanulate, thorny, with regular, circular pores. Abdomen wider, campanulate, with a small number of very large, regular, hexagonal meshes, and stout spines in the nodal points. Peristome with eight strong conical feet, which are nearly parallel, little curved (convex at the outside), and sometimes all of the same size (equal to the length of the shell); at other times different, four larger alternating with four smaller feet.
Dimensions.—Length of the three joints, a 0.02, b 0.05, c 0.08; breadth, a 0.025, b 0.07, c 0.1.
Habitat.—Fossil in Barbados.
10. Alacorys octacantha, n. sp.
Shell spiny, with deep collar stricture. Length of the three joints = 2 : 8 : 6, breadth = 3 : 7 : 7. Cephalis ovate, with a short, conical horn. Thorax pear-shaped, spiny, with regular, circular pores, similar to Cycladophora erinaceus, Ehrenberg (1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. fig. 2). Abdomen truncate, conical, with irregular, roundish pores, and eight stout, straight, thorny, divergent ribs of equal size, which are prolonged into eight free, conical, spiny feet of the same length.
Dimensions.—Length of the three joints, a 0.04, b 0.16. c 0.12; breadth, a 0.06, b 0.14, c 0.14.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
Definition.—Peristome armed with nine feet, three of which are primary or perradial, the other six secondary or interradial.
11. Alacorys enneacantha, n. sp.
Shell papillate, with slight collar stricture. Length of the three joints = 2 : 4 : 8, breadth = 3 : 6 : 9. Cephalis hemispherical, with a stout, conical horn of twice the length. Thorax campanulate, with subregular, circular pores, and small, conical papillæ. Thorax wider, campanulate, with circular pores, and conical papillæ of three times the size. Peristome with nine widely divergent, little curved, conical feet, about as long as the shell. Similar to Podocyrtis ventricosa, Ehrenberg (1875, loc. cit., Taf. xvi. fig. 3), different mainly in the feet.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.08; breadth, a 0.03, b 0.06, c 0.09.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
12. Alacorys gigas, n. sp.
Shell thorny, with distinct collar stricture. Length of the three joints = 1 : 4 : 2, breadth = 1 : 5 : 4. Cephalis ovate, with a short, conical horn of about half the length. Thorax campanulate, thorny, with small, regular, circular pores, very similar to Cycladophora gigas, Ehrenberg (loc. cit., 1875, p. 68, Taf. xviii. fig. 1). Abdomen truncate, conical, smooth, with irregular, roundish pores, and nine stout and straight, little divergent ribs, which are prolonged into nine cylindrical, pointed feet of the same length.
Dimensions.—Length of the three joints, a 0.05, b 0.2, c 0.1; breadth, a 0.05, b 0.25, c 0.2.
Habitat.—Fossil in Barbados.
Definition.—Peristome with numerous (ten to twenty or more) prominent feet, three or four of which are primary and perradial, the others secondary and interradial.
13. Alacorys dodecantha, n. sp.
? Podocyrtis schomburgkii, var., Bury, 1862, Polycystins of Barbados, Taf. xii. fig. 3.
Shell smooth, with slight collar stricture. Length of the three joints = 1 : 3 : 4, breadth = 1 : 4 : 7. Cephalis ovate, with a conical horn of the same length. Thorax campanulate, with regular, circular pores. From its margin arise twelve stout, little curved, radial beams, which are widely divergent, and connected in the middle part by a transverse circular ring, so that the abdomen exhibits twelve large triangular holes, and at the peristome, alternating with these, twelve free conical feet of the same length.
Dimensions.—Length of the three joints, a 0.04, b 0.09, c 0.11; breadth, a 0.03, b 0.12, c 0.22.
Habitat.—Central Pacific, Station 263, depth 2650 fathoms; also fossil in Barbados.
14. Alacorys carcinus, n. sp. (Pl. 74, fig. 9).
Calocyclas carcinus, Haeckel, 1879, Atlas, loc. cit.
Podocyrtis schomburgkii, var., Bury, 1862, Polycystins of Barbados, pl. i. fig. 2; pl. xii. fig. 4.
Shell rough, with distinct collar stricture. Length of the three joints = 1 : 4 : 4, breadth = 2 : 6 : 6. Cephalis hemispherical, with a large, cylindrical, bent spine of three times the length. Thorax inflated, campanulate, with large, regular, circular pores. Abdomen truncate, conical, with three to four transverse rows of regular, square pores, produced by eighteen divergent, straight ribs, which are connected by three to four horizontal rings. Distal end of the ribs prolonged into eighteen slender, conical feet, which are about as long as the thorax and slightly curved inwards.
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.08; breadth, a 0.05, b 0.12, c 0.12.
Habitat.—Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms; also fossil in Barbados.
15. Alacorys polyacantha, n. sp.
Shell spiny, with deep collar stricture. Length of the three joints = 3 : 9 : 10, breadth = 4 : 12 : 16. Cephalis hemispherical, with a stout conical horn of the same length. Thorax campanulate, with regular, circular pores and conical spines, increasing in size towards the deep lumbar stricture. Abdomen truncate, conical, with twenty to thirty divergent, straight ribs, which are connected by four to six transverse rings, and prolonged into free conical feet of half the length. Therefore four to six transverse rings of regular, square pores occur.
Dimensions.—Length of the three joints, a 0.03, b 0.09, c 0.1; breadth, a 0.04, b 0.12, c 0.16.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
16. Alacorys ornata, Haeckel.
Cryptoprora ornata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. v. fig. 8.
Shell ovate, smooth, without external strictures, but with two internal annular septa. Length of the three joints = 3 : 5 : 4, breadth = 3 : 6 : 5. Cephalis subspherical, partly enclosed by the uppermost part of the thorax, without horn, or with a small rudimentary horn. Pores subregular, circular, half as broad in the cephalis as in the two other joints. Thorax campanulate. Abdomen truncate, with eighteen to twenty-four parallel, vertical, longitudinal ribs, which are prolonged into slender, free, conical feet of the same length. (This remarkable species may be derived from Carpocanium by apposition of a third joint.)
Dimensions.—Length of the three joints, a 0.03, b 0.05, c 0.04; breadth, a 0.03, b 0.06, c 0.05.
Habitat.—Fossil in Barbados.
Definition.—Theophormida (vel Tricyrtida multiradiata aperta) with four to six or more radial ribs in the abdomen, the terminal mouth of which is truncate, without feet.
The genus Cycladophora differs from the preceding Alacorys, its probable ancestral genus, in the absence of free terminal feet, the radial ribs of the abdomen being connected by transverse beams throughout their whole length. The number of the regularly disposed ribs (four to six or more) may also here be used for the distinction of different subgenera.
Definition.—Abdomen with four radial ribs, opposite in pairs in two meridian planes, perpendicular one to another.
1. Cycladophora gœtheana, n. sp. (Pl. 65, fig. 5).
Shell shaped like a lantern, with two sharp strictures. Length of the three joints = 1 : 2 : 12, breadth = 1 : 4 : 7. Cephalis hemispherical, with a slender pyramidal horn of three times the length. Thorax twice as large, thorny, hemispherical, with regular, circular pores. Abdomen very long, nearly four-sided prismatic, with four superior smaller, and four inferior larger holes; the former separated by four short, divergent, perradial, the latter by four long, parallel, vertical, interradial bars. Mouth square, four-lobed. Dedicated to Wolfgang Goethe.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.24; breadth, a 0.03, b 0.07, c 0.1 to 0.14.
Habitat.—Central Pacific, Stations 265 to 269, depth 2550 to 2900 fathoms.
2. Cycladophora tetrapleura, n. sp.
Shell very similar to the preceding species, but differing in the following characters: Cephalis conical, with a horn of the same length. Thorax campanulate. Four ribs of the abdomen not parallel and vertical, but more or less divergent. Length of the three joints = 1 : 2 : 8, breadth = 1 : 2 : 4. Whole shell slender, pyramidal. Mouth square, four-lobed.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.24; breadth, a 0.03, b 0.06, c 0.12.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
3. Cycladophora lanterna, n. sp.
Shell very similar to the two preceding species, but differing in the following characters. Cephalis subspherical, with a thick, pyramidal horn of the same breadth, and three times the length. Thorax hemispherical, with circular, hexagonally-framed pores. Abdomen ovate, with four convex ribs, and twelve large holes, four superior smaller pentagonal, four intermediate very large, ovate, and four inferior, small, triangular holes. Mouth little constricted, nearly circular.
Dimensions.—Length of the three joints, a 0.025, b 0.05, c 0.22; breadth, a 0.025, b 0.08, c 0.11.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
Definition.—Abdomen with six radial ribs (three primary or perradial, and three alternate, secondary or interradial).
4. Cycladophora hexapleura, n. sp.
Lanterna chinensis, Bury, 1862, Polycystins of Barbados, pl. xiii. fig. 7.
Shell shaped like a lantern, with six sides and two sharp strictures. Length of the three joints = 1 : 2 : 8, breadth = 1 : 2 : 4. Cephalis hemispherical, with a conical spine of the same length. Thorax twice as large, hemispherical, with regular, circular pores. Abdomen nearly six-sided prismatic, with six descending, little curved ribs, and eighteen large holes between them; six superior holes interradial, ovate, six intermediate holes very large, perradial, ovate, six inferior holes triangular, interradial. Mouth six-lobed.
Dimensions.—Length of the three joints, a 0.02, b 0.04, c 0.16; breadth, a 0.03, b 0.06, c 0.1.
Habitat.—Fossil in Barbados.
5. Cycladophora pyramidalis, n. sp.
Podocyrtis sp., Bury, 1862, Polycystins of Barbados, pl. xii. fig. 2.
Shell slender, pyramidal, with six sides and two slight strictures. Length of the three joints = 1 : 4 : 12, breadth = 1 : 4 : 8. Cephalis subspherical, with a conical horn of twice the length. Thorax conical, with regular, circular pores. Abdomen truncate, pyramidal, with six strong, divergent, straight ribs, which are connected by five to six transverse, hexagonal rings; therefore six longitudinal rows of large, roundish, quadrangular meshes (four to five meshes in each row). Mouth hexagonal.
Dimensions.—Length of the three joints, a 0.025, b 0.1, c 0.3; breadth, a 0.03, b 0.1, c 0.2.
Habitat.—Fossil in Barbados.
6. Cycladophora spinosa, n. sp.
Shell spiny, with two deep strictures. Length of the three joints = 1 : 4 : 3, breadth = 1 : 5 : 4. Cephalis subspherical, with a stout conical horn of the same length. Thorax ovate, with regular, circular pores, and numerous conical spines. Abdomen truncate, conical, with irregular, roundish pores, and six strong, divergent ribs. Mouth circular.
Dimensions.—Length of the three joints, a 0.03, b 0.12, c 0.09; breadth, a 0.03, b 0.15, c 0.12.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms; fossil in Barbados.
Definition.—Abdomen with nine radial ribs (three primary or perradial, and six secondary or interradial).
7. Cycladophora enneapleura, n. sp.
Shell spiny, with two sharp strictures. Length of the three joints = 1 : 5 : 3, breadth = 2 : 7 : 4. Cephalis hemispherical, with a conical horn of twice the length. Thorax campanulate, with regular, circular pores, and conical thorax. Abdomen cylindrical, with nine straight, parallel ribs, and irregular, roundish pores. Mouth circular. (Similar to Cycladophora gigas, Ehrenberg, 1875, loc. cit., Taf. xviii. fig. 1, but differing in the possession of nine abdominal ribs.)
Dimensions.—Length of the three joints, a 0.03, b 0.15, c 0.1; breadth, a 0.06, b 0.2, c 0.12.
Habitat.—South Pacific, Station 295, depth 1500 fathoms.
8. Cycladophora nonagona, n. sp.
Shell spiny, with two distinct strictures. Length of the three joints = 3 : 10 : 7, breadth = 2 : 9 : 8. Cephalis pear-shaped, with a stout pyramidal horn of the same length. Thorax pear-shaped, with regular, circular pores, and conical horns, increasing in size towards the base. Abdomen truncate, pyramidal, with nine straight, spinulate ribs, and nine even faces between them, with irregular, roundish pores. Mouth nonagonal.
Dimensions.—Length of the three joints, a 0.06, b 0.2, c 0.14; breadth, a 0.05, b 0.18, c 0.16.
Habitat.—Fossil in Barbados.
Definition.—Abdomen truncate, conical or campanulate, with numerous (ten to twenty or more) divergent ribs. Mouth wide open, truncate.
9. Cycladophora pantheon, n. sp. (Pl. 68, fig. 3).
Shell dome-shaped, with slight collar and deep lumbar stricture. Length of the three joints = 1 : 6 : 5, breadth = 1 : 7 : 8. Cephalis small, with a conical horn of the same length. Thorax cupola-shaped, with large, regular, circular pores, and numerous pyramidal tubercles. Abdomen with twelve (sometimes eleven or thirteen) slender, divergent ribs, which are connected at equal distances by four to six horizontal rings, and so produce twelve longitudinal rows of large, regular, square meshes.
Dimensions.—Length of the three joints, a 0.02, b 0.12, c 0.1; breadth, a 0.03, b 0.14, c 0.15.
Habitat.—Central Pacific, Stations 263 to 274, depth 2350 to 2925 fathoms.
10. Cycladophora dodecapleura, n. sp.
Shell cupola-shaped, with two deep strictures. Length of the three joints = 2 : 5 : 6, breadth = 2 : 7 : 10. Cephalis hemispherical, with a conical horn of twice the length. Thorax subspherical, truncate at both poles, thorny, with regular, circular pores. Abdomen in the upper half with a coronal of twelve large ovate holes, separated by twelve divergent, slender ribs, in the lower half with curved, convergent prolongations of the twelve ribs, and numerous small, irregular, roundish pores.
Dimensions.—Length of the three joints, a 0.015, b 0.05, c 0.06; breadth, a 0.02, b 0.07, c 0.1.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
11. Cycladophora campanula, n. sp.
Shell campanulate, with two slight strictures. Length of the three joints = 2 : 4 : 5, breadth = 2 : 6 : 10. Cephalis ovate, with a conical horn of the same length. Thorax campanulate, rough, with regular, circular pores. Abdomen dilated, with fifteen to twenty slender, divergent, little curved ribs, which are connected by two or three horizontal rings, and from two or three transverse rows of large, roundish, square pores.
Dimensions.—Length of the three joints, a 0.04, b 0.08, c 0.1; breadth, a 0.04, b 0.12, c 0.2.
Habitat.—North Atlantic, Bermuda, surface; also fossil in Barbados.
12. Cycladophora spatiosa, Ehrenberg.
Cycladophora spatiosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xviii. figs. 5, 6.
Shell campanulate, with two slight strictures. Length of the three joints = 2 : 6 : 9, breadth = 3 : 8 : 14. Cephalis subspherical, with a conical horn of the same length. Thorax campanulate, smooth, with regular, circular pores. Abdomen truncate, conical, with sixteen to twenty-four divergent ribs, which are straight or slightly curved, and connected by from four to six transverse, circular rings. The large regular meshes, so produced, form sixteen to twenty-four longitudinal series, and are rounded in the upper, square in the lower transverse rows.
Dimensions.—Length of the three joints, a 0.02, b 0.06, c 0.09; breadth, a 0.03, b 0.08, c 0.14.
Habitat.—Fossil in Barbados.
13. Cycladophora favosa, n. sp. (Pl. 62, figs. 5, 6).
Shell dome-shaped, without collar stricture, but with a deep lumbar stricture. Cephalis flat, cap-shaped, without horn, or with a rudimentary conical horn, with small circular pores. Length of the three joints = 1 : 4 : 3, breadth = 2 : 5 : 4. Thorax subspherical, rough, with regular, circular, hexagonally-framed pores. Abdomen truncate, conical, with eighteen to twenty-four prominent ribs; between every two ribs only two or three ovate pores occur. Mouth circular, with eighteen to twenty-four teeth. The shape of the abdomen is rather variable (figs. 5, 6).
Dimensions.—Length of the three joints, a 0.02, b 0.08, c 0.06; breadth, a 0.04, b 0.09, c 0.07.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
Definition.—Abdomen nearly cylindrical or prismatic, with numerous (ten to twenty or more) straight, vertical, parallel ribs. Mouth wide open, truncate.
14. Cycladophora fenestrata, n. sp. (Pl. 68, fig. 2).
Shell rough, with two slight strictures. Length of the three joints = 1 : 5 : 5, breadth = 1 : 6 : 5. Cephalis conical, with a conical, dimpled horn of twice the length. Thorax nearly spherical, with regular, circular pores, and small conical spines. Abdomen cylindrical, with eighteen stout, parallel, vertical ribs, which are connected by six to eight horizontal, circular rings; therefore regular transverse and longitudinal rows of square or circular pores occur. Mouth truncate, circular.
Dimensions.—Length of the three joints, a 0.02, b 0.1, c 0.1; breadth, a 0.03, b 0.12, c 0.1.
Habitat.—Central Pacific, Station 265, depth 2900 fathoms.
15. Cycladophora stiligera, Ehrenberg.