Shell nut-shaped, tuberculate, with slight sagittal stricture and scattered small circular pores. Basal plate with four large collar pores (sometimes surrounded by several small peripheral pores). Apical horn slender, conical, as long as the shell. Feet sixteen to twenty, laminated and truncate, of the same length, nearly vertical and parallel.

Dimensions.—Shell 0.06 long, 0.08 broad; horn and feet 0.05 to 0.07 long.

Habitat.—Fossil in Barbados.

8. Petalospyris anthemis, n. sp.

Shell nut-shaped, spinulate, with deep sagittal stricture and irregular, roundish pores. Basal plate with four large pores of equal size. Apical horn conical, twice as long as the shell. Feet twenty to thirty, laminated and truncate, as long as the shell, divergent.

Dimensions.—Shell 0.05 long, 0.08 broad; horn 0.1 long, feet 0.6 long.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

9. Petalospyris tessaromma, n. sp.

Shell subspherical, with slight sagittal stricture and few small pores; on each side of the stricture four larger, square, annular pores. Basal plate with four large collar pores (two larger cardinal and two smaller jugular pores). Horn and feet conical, about half as long as the shell. Feet twenty to twenty-five, slightly curved, convergent.

Dimensions.—Shell diameter 0.08; horn and feet 0.04.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms; also fossil in Barbados.

Subgenus 4. Petalospyromma, Haeckel.

Definition.—Basal plate with numerous (six or more) collar pores, commonly three or four larger central, and six to twelve smaller peripheral pores.

10. Petalospyris novena, n. sp. (Pl. 83, fig. 12).

Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with nine pores (three large primary and three alternate pairs of small secondary pores). Nine long corresponding feet, twice to four times as long as the shell (three very thick primary, and three alternate pairs of thin secondary feet). All feet cylindrical, curved, widely divergent. Horn conical.

Dimensions.—Shell 0.06 long, 0.08 broad; horn and feet 0.15 to 0.25.

Habitat.—Indian Ocean (Cocos Islands), Rabbe, surface.

11. Petalospyris argiscus, Ehrenberg.

Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with nine pores (three larger central and three alternate pairs of smaller peripheral pores). Apical horn slender, spindle-shaped, about as long as the shell. Twenty to twenty-five feet, of the same length, broad, lamellar and truncate, nearly vertical, slightly divergent.

Dimensions.—Shell 0.06 long, 0.1 broad; horn and feet 0.05 to 0.07 long.

Habitat.—Fossil in Barbados.

12. Petalospyris papillata, n. sp.

Shell nearly cubical, papillate, without external sagittal stricture, with small, irregular, roundish pores. Basal plate with six pores (three larger and three alternate smaller). Apical horn conical, half as long as the shell. Feet twenty to thirty, one-half to one-third as long, conical, divergent.

Dimensions.—Shell diameter 0.09; horn 0.04 long, feet 0.03 to 0.05 long.

Habitat.—North Atlantic, Station 353, depth 2965 fathoms.

13. Petalospyris dictyocubus, n. sp. (Pl. 86, fig. 6).

Shell nearly cubical, smooth, without external stricture, but with a complete, parietal, square, sagittal ring. On each side of the ring four pairs of larger pores, whilst the lateral pores are smaller and more numerous. Basal plate also with four pairs of larger pores and smaller lateral pores. Apical horn and basal feet short, pyramidal, scarcely one-fourth as long as the shell. The three primary feet are larger than the six to nine secondary feet.

Dimensions.—Shell diameter 0.08; horn and feet 0.02 long.

Habitat.—Central Pacific, Station 274, surface.

14. Petalospyris bellidiastrum, n. sp.

Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, roundish pores. Basal plate with twelve pores (four central larger and eight peripheral smaller pores). Apical horn slender, conical, about as long as the shell (sometimes ramified at the distal end). Feet sixteen to twenty, broadly lamellar, truncate, divergent, about as long as the shell.

Dimensions.—Shell 0.08 long, 0.1 broad; horn and feet 0.07 to 0.09 long.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms; also fossil in Barbados.

15. Petalospyris dinoceras, n. sp. (Pl. 87, fig. 12).

Shell nut-shaped, mammillate, without external stricture, but with complete external sagittal ring. Pores subregular, circular. Basal plate with four large central pores, surrounded by a circle of twelve to twenty small peripheral pores. Apical horn very large, spindle-shaped, one and a half times as long as the shell. Feet twenty-five to thirty, broadly lamellar, truncate, divergent, about as long as the shell.

Dimensions.—Shell 0.11 long, 0.13 broad; horn 0.15 long, feet 0.09 long.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

16. Petalospyris furcata, n. sp.

Shell nut-shaped, smooth, with sharp sagittal stricture. Pores numerous, small, and circular; no larger annular pores. Basal plate with four larger and four alternate pairs of smaller pores. Horn conical, about as long as the shell. Feet fifteen to twenty, broadly lamellar, about twice as long as the shell, in the distal half forked.

Dimensions.—Shell 0.04 long, 0.06 broad; horn 0.05 long, feet 0.1 long.

Habitat.—South Pacific, Station 300, depth 1375 fathoms.

17. Petalospyris lobata, n. sp. (Pl. 87, fig. 13).

Shell subspherical, smooth, with slight sagittal stricture. Pores small, roundish; on each side of the ring two pairs of larger annular pores. Basal plate with four pores. Horn stout, three-sided prismatic, half as long as the shell. Feet twelve to sixteen, lamellar, lobate (the most part with three lobes), nearly vertical, about as long as the shell.

Dimensions.—Shell diameter 0.05; horn 0.03, feet 0.05 long.

Habitat.—South Atlantic, Station 335, depth 1425 fathoms.

Genus 464. Anthospyris,^[82] Haeckel, 1881, Prodromus, p. 443.

Definition.—Zygospyrida with numerous (seven to nine or more) basal feet and three coryphal horns.

The genus Anthospyris differs from the preceding Petalospyris, its ancestral form, in the possession of three horns on the coryphal face (one odd middle apical horn and two paired frontal horns, one on each side). The former therefore bears to the latter the same relation that Triceraspyris does to Tripospyris and Liriospyris to Hexaspyris.

1. Anthospyris mammillata, n. sp. (Pl. 87, fig. 16).

Shell nut-shaped, mammillate, with deep sagittal stricture and irregular, polygonal pores. Basal plate with two large ovate pores (?). The pediculate apical horn and the two frontal horns stout and short, conical, twice to three times as large as the conical papillæ of the surface. Feet twelve to fifteen, lanceolate lamellar, pointed, divergent, about as long as the shell.

Dimensions.—Shell 0.05 long, 0.08 broad; horns 0.03, feet 0.04 long.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms.

2. Anthospyris spathulata, n. sp. (Pl. 87, fig. 15).

Shell subspherical, thorny, with slight sagittal stricture and irregular, roundish pores. Basal plate with three large pores. The three horns spindle-shaped, half as long as the ten to twelve thin feet, which are pediculate, shovel-shaped, a little divergent, and shorter than the shell.

Dimensions.—Shell 0.05 diameter; horn 0.02 long, feet 0.04 long.

Habitat.—North Pacific, Station 250, depth 3050 fathoms.

3. Anthospyris diaboliscus, Haeckel.

Shell nut-shaped, smooth, with slight sagittal stricture and small circular pores. Basal plate with four large pores. Apical horn straight conical, frontal horns curved laterally. Feet nine to twelve, of about the same length as the horns and the shell, broad lamelliform, truncate, nearly vertical, slightly curved.

Dimensions.—Shell 0.04 long, 0.07 broad; horns and feet 0.05 to 0.07 long.

Habitat.—Fossil in Barbados.

4. Anthospyris arachnoides, Haeckel.

Shell nut-shaped, tuberculate, with slight sagittal stricture and irregular, polygonal pores. Basal plate with four large pores (?). Apical horn straight, conical, longer than the two curved lateral horns. Feet ten, slender, S-shaped, widely divergent, about as long as the shell is broad.

Dimensions.—Shell 0.05 long, 0.08 broad; horns 0.03 to 0.05 long, feet 0.08 long.

Habitat.—Mediterranean (Messina), Atlantic, Station 354, surface.

5. Anthospyris aculeata, n. sp. (Pl. 86, fig. 5).

Shell campanulate, spiny, with deep sagittal stricture and irregular, roundish pores. On each side of the stricture three pairs of larger annular pores. Basal plate with two large square pores. The three horns of the same size as, and similar form to, the ten to fifteen feet, slender pyramidal, straight, divergent, about half as long as the shell. (This species is very variable and closely allied to Ceratospyris.)

Dimensions.—Shell diameter 0.08 to 0.12; horns and feet 0.04 to 0.06 long.

Habitat.—Central Pacific, Stations 266 to 274, surface.

6. Anthospyris doronicum, n. sp. (Pl. 87, fig. 18).

Shell nut-shaped, spiny, with a deep sagittal stricture and small circular pores. On each side of the stricture two pairs of very large square annular pores. Basal plate with four larger collar pores and a corona of numerous small peripheral pores. Three horns spindle-shaped, divergent, about half as long as the shell. Feet twenty-five to thirty, broad, lamellar, lanceolate, pointed, divergent, nearly as long as the shell.

Dimensions.—Shell 0.1 long, 0.13 broad; horns 0.06, feet 0.09 long.

Habitat.—South Pacific, Station 296, depth 1825 fathoms.

7. Anthospyris tragopogon, n. sp. (Pl. 87, fig. 17).

Shell nut-shaped, tuberculate, with distinct sagittal stricture and small regular circular pores. Basal plate with numerous small pores. Apical horn very large, spindle-shaped, twice as long as the shell; frontal horns small, scarcely one-fourth as long, curved laterally. Feet twenty-five to thirty, three to four times as long as the shell, lamellar, lanceolate, pointed, parallel, vertical.

Dimensions.—Shell 0.08 long, 0.11 broad; apical horn 0.16, feet 0.2 long.

Habitat.—Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms.

Genus 465. Ceratospyris,^[83] Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.

Definition.—Zygospyrida with numerous (seven to twelve or more) basal feet and numerous coryphal horns.

The genus Ceratospyris differs from all the other Zygospyrida in the possession of numerous large spines on the surface of the shell, which usually exhibits only a small number of large pores or meshes. The lower spines which cover the inferior or basal face of the shell (usually nine to twelve or more) may be compared to the descending "basal feet" of the other Zygospyrida; the upper spines, however, which cover the superior or coryphal face (usually six to nine, rarely more), may be regarded as "coryphal horns." In many species of this genus the lattice-work of the shell is of a peculiar loose kind, with few large meshes, resembling the wicker-work of the Plectanida.

Subgenus 1. Lophospyris, Haeckel, 1881, Prodromus, p. 443.

Definition.—Spines simple, not branched. Meshes of the shell usually polygonal, or roundish with polygonal frames. Bars of the network prismatic.

1. Ceratospyris polygona, n. sp. (Pl. 86, fig. 1).

Shell polyhedral, with deep sagittal stricture, studded with twenty-four to thirty long simple straight slender pyramidal spines, which are as long as the shell or longer. All pores large, polygonal. On the frontal and the occipital face two pairs of very large pores only, the superior pentagonal, larger than the inferior tetragonal. Basal plate with two triangular pores. Bars of the loose framework three-sided prismatic, thin.

Dimensions.—Shell 0.08 long, 0.12 broad; spines 0.06 to 0.12 long.

Habitat.—Cosmopolitan; Atlantic, Indian, Pacific, surface.

2. Ceratospyris pentagona, Ehrenberg.

Shell polyhedral, with slight sagittal stricture, studded with twenty-four to thirty small simple conical spines, which are shorter than one-fourth of the shell. Most pores pentagonal. On the frontal and the occipital face two pairs of large pores only, the superior smaller than the inferior. Basal plate with four quadrangular pores. Bars of the network prismatic, thin.

Dimensions.—Shell 0.07 long, 0.11 broad; spines 0.01 to 0.02 long.

Habitat.—Cosmopolitan; Atlantic, Indian, Pacific, surface.

3. Ceratospyris allmersii, n. sp. (Pl. 86, fig. 3).

Shell polyhedral, with slight sagittal stricture, studded with thirty to forty prismatic spines which are not longer than half the shell. Most pores pentagonal. On the frontal face two, on the occipital three pairs of larger pores; the inferior the largest. Basal plate with two rhomboidal pores (?). Bars of the network three-sided prismatic, thin. Dedicated to my dear friend, the excellent poet and naturalist, Hermann Allmers, of Rechtenfleth.

Dimensions.—Shell 0.08 long, 0.12 broad; spines 0.01 to 0.03.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

4. Ceratospyris mulderi, n. sp. (Pl. 86, fig. 4).

Shell polyhedral, with deep sagittal stricture, studded with fifty to seventy prismatic spines; two inferior (pectoral) spines about as long as the shell, the others much shorter. Pores polygonal. On the frontal and the occipital face one pair of very large pores. Basal plate with two distinctly hexagonal pores. Bars of the loose network prismatic. Dedicated to my dear friend, the excellent author and painter, Ludwig Mulder, of the Hague.

Dimensions.—Shell 0.07 long, 0.12 broad; spines 0.01 to 0.08.

Habitat.—Indian Ocean, Sunda Straits (Rabbe), surface.

5. Ceratospyris strasburgeri, n. sp. (Pl. 86, fig. 2).

Shell polyhedral, with slight sagittal stricture, studded with thirty to forty prismatic spines, which are about half as long as the shell (two or four inferior are longer). Pores roundish, with polygonal frames. On the frontal and occipital face two pairs of larger pores (the superior smaller). Basal plate with two large pentagonal pores. Bars of the network prismatic. Dedicated to my dear friend, the celebrated botanist, Professor Eduard Strasburger, of Bonn.

Dimensions.—Shell 0.07 long, 0.1 broad; spines 0.02 to 0.04.

Habitat.—Western Tropical Pacific, Station 225, depth 4475.

6. Ceratospyris mülleri, Stöhr.

Shell polyhedral, with slight collar stricture, studded with forty to fifty pyramidal spines, shorter than half the shell. Pores circular, with pentagonal frames of the same breadth, all nearly of equal size. (Basal plate with four pores?) Bars of the network prismatic. Dedicated to Johannes Müller.

Dimensions.—Shell 0.08 long, 0.1 broad; spines 0.01 to 0.03.

Habitat.—Fossil in Tertiary rocks of Sicily, Grotte (Stöhr).

7. Ceratospyris krausei, n. sp. (Pl. 86, fig. 10).

Shell nut-shaped, with deep sagittal stricture, studded with forty to fifty strong conical spines; six basal spines as long as the shell and two to three times as long as the others. Pores roundish polygonal, twice to three times as broad as the bars; two pairs of larger pores on each side of the ring. (Basal plate with four large pores?) Bars of the network rounded, thick. Dedicated to my dear friend, the excellent author, Ernst Krause (Carus Sterne), of Berlin.

Dimensions.—Shell 0.06 long, 0.09 broad; spines 0.03 to 0.08.

Habitat.—Western Tropical Pacific (Philippine Sea), Station 206, depth 2100 fathoms.

8. Ceratospyris preyeri, n. sp. (Pl. 86, fig. 9).

Shell nut-shaped, with slight sagittal stricture, studded with ten to twelve longer club-shaped spines (about as long as the shell) and numerous smaller conical spines. Pores irregular, roundish, numerous; two pairs of larger pores on each side of the ring. Basal plate with four large pores. Bars of the network rounded. Dedicated to my honoured friend and colleague, the celebrated investigator of psychical ontogeny, Professor William Preyer, of Jena.

Dimensions.—Shell 0.07 long, 0.09 broad; spines 0.02 to 0.08 long.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

9. Ceratospyris echinus, Ehrenberg.

Shell subspherical, with slight sagittal stricture, studded with numerous conical curved spines; six basal and one apical spine are larger than the others, about as long as the shell. Pores numerous, small, circular. Basal plate with numerous pores. Bars of the network roundish.

Dimensions.—Shell 0.05 long, 0.06 broad; spines 0.02 to 0.05 long.

Habitat.—Fossil in Barbados.

Subgenus 2. Cladospyris, Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.

Definition.—Spines forked or branched. Meshes roundish or polygonal.

10. Ceratospyris ramosa, Ehrenberg.

Shell nut-shaped, with slight sagittal stricture, studded with numerous conical, irregularly branched spines. The largest about as long as the shell. Pores irregular, roundish; on each side of the ring two pairs of larger pores. Basal plate with four pores. Bars of the network roundish.

Dimensions.—Shell 0.06 long, 0.08 broad; spines 0.02 to 0.08 long.

Habitat.—Fossil in Barbados.

11. Ceratospyris carnerii, n. sp. (Pl. 86, fig. 11).

Shell nut-shaped, with sharp sagittal stricture, studded with numerous pyramidal spines; two basal spines are larger, as long as the shell, and irregularly branched. Pores polygonal; on each side of the ring three pairs of larger pores. Basal plate with four large pores. Dedicated to my dear friend, the excellent monistic philosopher, B. von Carneri.

Dimensions.—Shell 0.09 long, 0.12 broad; spines 0.02 to 0.08 long.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

12. Ceratospyris calorrhiza, n. sp. (Pl. 87, fig. 19).

Shell nut-shaped, with deep sagittal stricture, studded with numerous conical strong spines, about one-fourth as long as the shell. Basal spines irregularly branched, with root-like ends. Pores irregular, roundish, some larger pores on each side of the ring. Basal plate with four larger pores. Bars of the network roundish.

Dimensions.—Shell 0.1 long, 0.14 broad; spines 0.02 to 0.04 long.

Habitat.—Central Pacific, Station 271, surface.

Genus 466. Gorgospyris,^[84] Haeckel, 1881, Prodromus, p. 443.

Definition.—Zygospyrida with numerous (seven to twelve or more) basal feet, without coryphal horns.

The genus Gorgospyris agrees with the three preceding genera in the possession of numerous basal feet, but differs from them in the complete absence of any horns on the coryphal face. It represents therefore the "hornless polypedal Zygospyrida," and may be derived from Petalospyris by loss of the original apical horn. The feet are commonly numerous, and often form a circle around the margin of the basal plate, similar to the circle of tentacles in many Medusæ (Gorgon).

Subgenus 1. Gorgospyrium, Haeckel.

Definition.—Feet simple, not branched.

1. Gorgospyris medusa, n. sp. (Pl. 87, fig. 1).

Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. Basal plate with three large collar pores (by mistake not correctly represented in the figure). Ten to twelve slender feet, twice as long as the shell, strongly curved and divergent, of equal length.

Dimensions.—Shell 0.06 long, 0.08 broad; feet 0.1 long.

Habitat.—North Pacific, Station 241, depth 2300 fathoms.

2. Gorgospyris medusetta, n. sp. (Pl. 87, fig. 2).

Shell misshaped, smooth, with deep sagittal stricture and irregular, roundish pores. Basal plate with three large collar pores, alternating with three pairs of smaller pores. Sixteen to twenty slender feet, about as long as the shell, slightly curved and divergent, of nearly equal length.

Dimensions.—Shell 0.05 long, 0.08 broad; feet 0.05 long.

Habitat.—Central Pacific, Station 274, depth 2750 fathoms.

3. Gorgospyris ehrenbergii, Haeckel.

Shell nut-shaped, smooth, with slight sagittal stricture and unequal circular pores. Basal plate with three large central pores, alternating with three pairs of smaller pores, and with a peripheral circle of smaller pores. Twenty-four to thirty short truncated feet, shorter than half the shell.

Dimensions.—Shell 0.05 long, 0.07 broad; feet 0.02 long.

Habitat.—Fossil in Barbados.

4. Gorgospyris polypus, n. sp. (Pl. 87, fig. 3).

Shell hemispherical, papillate, with slight sagittal stricture and subregular circular pores. Basal plate with four larger and four alternating smaller pores. Feet sixteen to twenty, slender, carved, divergent; four primary feet larger, twice to three times as long as the shell and the other feet.

Dimensions.—Shell 0.08 long, 0.1 broad; feet 0.1 to 0.2 long.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

5. Gorgospyris eurycolpos, n. sp. (Pl. 87, fig. 5).

Shell nut-shaped, rough, with deep sagittal stricture and irregular, roundish pores; two to three pairs of larger annular pores on each side of the stricture. Basal plate with four large collar pores. Feet eight, short, triangular, vertical, about one-fourth as long as the shell.

Dimensions.—Shell 0.08 long, 0.13 broad; feet 0.02 long.

Habits.—Central Pacific, Station 270, depth 2925 fathoms.

6. Gorgospyris liriope, n. sp. (Pl. 87, fig. 6).

Shell nut-shaped, thorny, with sharp sagittal stricture and irregular, roundish pores. Two pairs of larger annular pores on each side of the ring. Basal plate with two very large circular pores only. Eight to ten short feet vertical, about one-fourth as long as the shell, with an elegant papillate knob at the distal end.

Dimensions.—Shell 0.07 long, 0.1 broad; feet 0.02 long.

Habitat.—South Atlantic, Station 323, depth 1900 fathoms.

7. Gorgospyris lamellosa, n. sp.

Shell nut-shaped, tuberculate, with subregular circular pores. Basal plate with four larger and four alternate pairs of smaller pores. Feet fifteen to twenty-five, broad, lamellar, vertical, truncate, about as long as the shell, of irregular size and form, very variable.

Dimensions.—Shell 0.07 long, 0.1 broad; feet 0.05 to 0.1 long.

Habitat.—Fossil in Barbados.

Subgenus 2. Thamnospyris, Haeckel, 1881, Prodromus, p. 443.

Definition.—Feet divided or branched.

8. Gorgospyris schizopodia, n. sp. (Pl. 87, fig. 4).

Shell hemispherical, smooth, with slight sagittal stricture and small regular, circular pores. Basal plate with four large central and a circle of small pores. Feet fifteen to twenty, broad, lamellar, confluent at the base, about as long as the shell, irregularly divided or forked.

Dimensions.—Shell 0.06 long, 0.08 broad; feet 0.05 to 0.08 long.

Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.

9. Gorgospyris thamnopodia, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture and irregular, roundish pores. Basal plate with numerous small pores. Feet twenty to thirty, slender, curved, divergent, twice to three times as long as the shell, irregularly branched.

Dimensions.—Shell 0.08 long, 0.12 broad; feet 0.15 to 0.25 long.

Habitat.—Indian Ocean (Madagascar), Rabbe, surface.

Subfamily 8. Circospyrida, Haeckel, 1881, Prodromus, p. 443.

Definition.—Zygospyrida apoda, without descending basal feet.

Genus 467. Circospyris,^[85] Haeckel, 1881, Prodromus, p. 444.

Definition.—Zygospyrida without basal feet, with an apical horn.

The genus Circospyris and the following closely allied genus Dictyospyris represent together the small subfamily Circospyrida, differing from all other Zygospyrida in the absence of feet on the basal face. They have probably arisen from the Tripospyrida (Tripospyris) by reduction and loss of the feet (in the same way as the eradiate Cyrtoidea from the triradiate). But it is also possible that many of the Circospyrida (if not all) are derived directly from the Semantida (Clathrocircus) by the closing of the two lateral openings and by completing the framework.

1. Circospyris nucula, n. sp. (Pl. 95, fig. 13).

Shell nut-shaped, compressed, smooth, with prominent sagittal ring. On each side of the ring three to four pairs of very large annular polygonal pores. Lateral pores small and numerous, roundish. Basal plate with two large pores only. Horn slender, conical, shorter than half the shell.

Dimensions.—Shell 0.11 long, 0.13 broad.

Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.

2. Circospyris gigas, Haeckel.

Shell nut-shaped, tuberculate, with distinct sagittal stricture. On each side of the ring four pairs of larger annular pores. Lateral pores roundish, smaller. Basal plate with four large central and a circle of eight to twelve smaller peripheral pores. Horn cylindrical, about half as long as the shell (in the inverted figure of Ehrenberg directed downwards).

Dimensions.—Shell 0.1 to 0.15 long, 0.15 to 0.2 broad; horn 0.05 to 0.08 long.

Habitat.—Fossil in Barbados.

3. Circospyris tridentata, Haeckel.

Shell nut-shaped, smooth, with sharp sagittal stricture. On each side of the ring two pairs of large annular pores. Lateral pores roundish, smaller. Basal plate with six large pores. Horn slender, cylindrical, about as long as the shell, with three sharp teeth at the distal end.

Dimensions.—Shell 0.03 long, 0.05 broad; horn 0.03 long.

Habitat.—Fossil in Barbados.

Genus 468. Dictyospyris,^[86] Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.

Definition.—Zygospyrida without basal feet, and without coryphal horns.

The genus Dictyospyris, the last and simplest of the twenty-eight genera of Zygocyrtida, may be regarded either as a primordial ancestral form of this large family, or more probably as the last and most reduced form of it. In the former case the total absence of coryphal horns and basal feet is primary, in the latter case secondary, effected by phylogenetic reduction and loss. But it is also possible that in one part of the numerous species of this genus the former case, and in another the latter takes place, and that one part of Dictyospyris may be directly developed from the Semantida or Coronida (the lattice shell becoming complete), another part arising from the Tripospyrida or Dipospyrida (the horns and feet becoming lost).

Subgenus 1. Dictyospyrantha, Haeckel.

Definition.—Basal plate with two large pores only (the primary jugular pores of Semantis).

1. Dictyospyris distoma, n. sp. (Pl. 89, figs. 11, 12).

Shell nut-shaped, smooth, or somewhat tuberculate, with deep sagittal stricture. Pores not numerous, large, roundish-polygonal; three pairs of large annular pores on each side of the ring. Basal plate with two very large pentagonal roundish collar pores.

Dimensions.—Shell 0.06 long, 0.08 broad.

Habitat.—Central Pacific, Stations 265 to 268, depth 2700 to 2900 fathoms.

2. Dictyospyris stalactites, n. sp. (Pl. 89, fig. 7).

Shell nut-shaped, covered with irregular ramified tubercles (like stalactites), with deep sagittal stricture. Pores not numerous, large, irregular, roundish. Two pairs of large triangular pores on each side of the ring (the inferior larger). Basal plate with two very large semicircular collar pores.

Dimensions.—Shell 0.07 long, 0.09 broad.

Habitat.—Central Pacific, Station 272, depth 2600 fathoms; also fossil in Barbados.

3. Dictyospyris biloba, n. sp.

Shell subspherical, tuberculate, with slight sagittal stricture. Pores very numerous, small, circular. No larger pores on either side of the ring. Basal plate with two very large circular pores, surrounded by a circle of smaller pores.

Dimensions.—Shell 0.07 long, 0.08 broad.

Habitat.—North Pacific, Station 253, depth 3125 fathoms.

Subgenus 2. Dictyospyrella, Haeckel.

Definition.—Basal plate with three large collar pores (two paired posterior cardinal pores and an odd anterior sternal pore).

4. Dictyospyris triomma, n. sp.

Shell nut-shaped, smooth, with deep sagittal stricture. Pores not numerous, large, polygonal roundish, two pairs of very large annular pores on each side of the ring. Basal plate with three large triangular pores. No free internal procolumella.

Dimensions.—Shell 0.06 long, 0.09 broad.

Habitat.—Indian Ocean, Zanzibar (Pullen), depth 2200 fathoms.

5. Dictyospyris tristoma, Ehrenberg.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular, roundish. Three pairs of larger annular pores on each side of the ring. Basal plate with three large semi-circular pores (the sternal odd pore apparently halved by an internal free procolumella).

Dimensions.—Shell 0.05 long, 0.08 broad.

Habitat.—Fossil in Barbados and Sicily (Caltanisetta).

6. Dictyospyris triloba, Ehrenberg.

Shell nut-shaped, spinulate, without external stricture, but with a complete internal sagittal ring. Pores numerous, subregular circular; no larger annular pores. Basal plate with three large, heart-shaped two-lobed collar pores.

Dimensions.—Shell 0.05 long, 0.07 broad.

Habitat.—Fossil in Barbados.

7. Dictyospyris gigas, Bütschli.

Shell subspherical, smooth, with a half (ventral) sagittal stricture, and a nearly complete internal ring. Pores very numerous and small, circular. No larger annular pores. Basal plate with three large collar pores (the sternal odd pore apparently divided into two jugular pores by the visible free procolumella.) (Compare Circospyris gigas, p. 1072 = Dictyospyris gigas, Ehrenberg).

Dimensions.—Shell 0.1 long, 0.14 broad.

Habitat.—Fossil in Barbados.

Subgenus 3. Dictyospyrissa, Haeckel.

Definition.—Basal plate with four large collar pores (two larger posterior cardinal and two smaller anterior jugular pores).

8. Dictyospyris fenestra, Ehrenberg.