Legion III. NASSELLARIA, (continued 5)

Dimensions.—Shell 0.08 long, 0.09 broad; horn 0.05 long, feet 0.1 long.

Habitat.—Fossil in Barbados.

Genus 457. Aegospyris,^[75] Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida with five basal feet and three coryphal horns.

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

1. Aegospyris aequispina, n. sp.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores subregular circular. Basal plate with four large collar pores. Three horns and five feet all of equal size and similar form, slender conical, slightly curved, widely divergent, about as long as the shell.

Dimensions.—Shell 0.08 long, 0.11 broad; horns and feet 0.08 long.

Habitat.—Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms.

2. Aegospyris octospina, n. sp.

Shell nearly cubical, smooth, with slight sagittal stricture. Pores subregular circular; two pairs of larger pores on each side of the ring. Basal plate with four large pores. Two paired horns and four paired feet of equal size and similar form, S-shaped curved, twice as long as the shell. Odd horn and odd feet half as long, straight, conical.

Dimensions.—Shell 0.08 long, 0.09 broad; six paired spines 0.2 long, two odd spines 0.1 long.

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

3. Aegospyris longibarba, Haeckel.

Ceratospyris longibarba, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xxi. figs. 1, 2.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores subregular circular. Basal plate with four larger central, and eight smaller peripheral pores. Apical horn and caudal foot short, straight, conical; two frontal horns longer, curved; four paired feet slender, curved, twice as long as the shell.

Dimensions.—Shell 0.06 long, 0.08 broad; paired horns 0.03 long, paired feet 0.1 long.

Habitat.—Fossil in Barbados.

4. Aegospyris aegoceras, n. sp. (Pl. 95, fig. 10).

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish. Basal plate with three large pores. Apical horn and caudal foot short, straight, spindle-shaped; two frontal horns as long as the shell, strongly curved; four paired feet also curved, at the distal end forked, divergent; the tergal thinner and as long as the shell, the pectoral thicker and twice as long.

Dimensions.—Shell 0.07 long, 0.09 broad; pectoral feet 0.1 long.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

5. Aegospyris caprina, n. sp. (Pl. 86, fig. 8).

Shell nut-shaped, papillate, with sharp sagittal stricture. Pores irregular roundish, two pairs of larger pores on each side of the ring. Basal plate with six large pores. Eight spines all straight, subvertical and nearly parallel, cylindro-conical. Two frontal horns and two tergal feet about as long as the shell; odd horn shorter; odd foot longer. Two pectoral feet twice as long as the shell, club-shaped, with a spinulate knob at the distal end.

Dimensions.—Shell 0.06 long, 0.09 broad; pectoral feet 0.11 long.

Habitat.—Central Pacific, Station 271, surface.

Genus 458. Pentaspyris,^[76] Haeckel, 1881, Prodromus, p. 442.

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

The genus Pentaspyris differs from the two preceding genera in the absence of any coryphal horn, and represents therefore the pentapodal form among the hornless Zygospyrida.

1. Pentaspyris pentacantha, n. sp. (Pl. 95, fig. 11).

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, two pairs of larger pores on each side of the ring. Basal plate with four larger pores. All five feet cylindrical, S-shaped curved, strongly divergent, with few short branches, the two pectoral feet twice as long as the shell and the two tergal feet; odd caudal foot shorter.

Dimensions.—Shell 0.08 long, 0.13 broad; pectoral feet 0.2 long, tergal feet 0.1, caudal foot 0.06.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

2. Pentaspyris isacantha, n. sp.

Shell subspherical, smooth, with slight sagittal stricture. Pores small, regular circular. Basal plate with six large pores (?). All five feet equal, cylindrical, C-shaped curved, slightly divergent, about as long as the shell.

Dimensions.—Shell 0.08 long, 0.09 broad; feet 0.07 long.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

Subfamily 6. Therospyrida, Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida tetrapoda with two pairs of descending basal feet, one pair corresponding to the anterior or pectoral, the other pair to the posterior or tergal feet of the Hexaspyrida.

Genus 459. Zygospyris,^[77] Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida with two pairs of lateral feet and an apical horn.

The genus Zygospyris and the following three genera represent together the peculiar subfamily of Therospyrida. These always possess four basal feet, like the Tetraspyrida; but whilst in the latter group two feet are sagittal, and two lateral, in the Therospyrida there are no sagittal feet at all, but the four feet are opposed in two lateral pairs; the anterior pair corresponds to the pectoral, the posterior to the tergal feet of the Hexaspyrida and Pentaspyrida; from these latter the Therospyrida have been derived by loss of the sagittal feet.

1. Zygospyris quadrupes, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular roundish, on each side of the ring two pairs of larger pores. Apical horn conical, straight. Four feet equal, straight, divergent, conical, about as long as the shell and the horn.

Dimensions.—Shell 0.08 long, 0.11 broad; horn and feet 0.1 long.

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

2. Zygospyris equus, n. sp. (Pl. 83, fig. 16).

Shell subspherical, rough, with slight sagittal stricture. Pores small and numerous, subregular circular; no larger annular pores. Apical horn cylindrical, half as long as the shell. Two pectoral feet somewhat smaller than the two tergal feet, about as long as the shell, slightly divergent, cylindrical. The distal ends of the feet and of the horn form an ovate, dimpled and spinulate cone.

Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.04 long, feet 0.06 long.

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

Genus 460. Elaphospyris,^[78] Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida with two pairs of lateral feet and three coryphal horns.

The genus Elaphospyris differs from the preceding Zygospyris, its ancestral form, in the possession of three coryphal horns (one odd apical and two paired frontal horns), and therefore bears to it the same relation that Triceraspyris does to Tripospyris among the Tripospyrida.

Subgenus 1. Giraffospyris, Haeckel, 1881, Prodromus, p. 442.

Definition.—Feet simple, not branched nor forked.

1. Elaphospyris heptaceros, Haeckel.

Ceratospyris heptaceros, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 2.

Giraffospyris heptaceros, Haeckel, 1881, Prodromus, p. 442.

Shell nut-shaped, tuberculate, with slight sagittal stricture and subregular circular pores. Basal plate with four large pores. Apical horn small, conical, shorter than the two curved lateral horns, which are as long as the shell. Caudal and sternal feet small, conical, straight. Two pectoral feet slender, divergent, S-shaped, about as long as the shell.

Dimensions.—Shell 0.05 long, 0.07 broad; horns and feet 0.02 to 0.08 long.

Habitat.—Fossil in Barbados.

2. Elaphospyris capricornis, n. sp.

Shell nut-shaped, spiny, with slight sagittal stricture and numerous small circular pores. Basal plate with four large pores. Three horns slender, simple, about as long as the shell, the middle one straight, the two lateral curved. Four feet of nearly equal size, slender, curved, divergent, simple, twice as long as the shell and the horns.

Dimensions.—Shell 0.07 long, 0.09 broad; horns 0.08 long, feet 0.15 long.

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

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

Definition.—Feet branched or forked.

3. Elaphospyris damaecornis, n. sp. (Pl. 84, fig. 10).

Shell flat and broad, nearly triangular, with slight sagittal stricture and irregular roundish pores; two very large pores on the frontal and on the occipital face, opposite on both edges of the broad sagittal ring. Basal plate with four large central and several smaller lateral pores. Three horns about half as long as the shell, with two to six irregular branches. Four feet of equal size, about as long as the shell, divergent, forked, with four to six irregular terminal branches. (The shell in fig. 10 is seen from the apical side.)

Dimensions.—Shell 0.09 long, 0.13 broad; horns 0.05 long, feet 0.1 long.

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

4. Elaphospyris cervicornis, n. sp. (Pl. 86, fig. 13).

Shell polyhedral, spiny, with deep sagittal stricture and a small number of large roundish pores; two pairs of large pores on each side of the ring. Basal plate with four pores. Three large horns as long as the shell arise from the apex between smaller conical spines; the middle odd horn simple, the two lateral each with a pair of branches. Two pectoral feet very large, divergent, with broad and irregular distal ramification, twice as long as the shell and as the two tergal feet, which are less branched. (Fig. 13 exhibits the shell from the dorsal side.)

Dimensions.—Shell 0.09 long, 0.11 broad; horns and smaller feet 0.07 to 0.09 long; pectoral feet 0.16 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

5. Elaphospyris alcicornis, n. sp. (Pl. 86, fig. 12).

Shell nut-shaped, spiny, with sharp sagittal stricture and large roundish pentagonally framed pores; three pairs of larger pores on each side of the ring. Basal plate with four larger and four alternate smaller pores. There arise from the apex, between smaller spines, three large, divergent, pyramidal horns, which are nearly as long as the shell, and connected by an arched frontal bridge. Two pectoral feet very large, divergent, prismatic, longer than the shell, and at the distal end with a bunch of thick spines. Two tergal feet half as long and thick, simple (in the figure hidden behind the large pectoral feet).

Dimensions.—Shell 0.09 long, 0.11 broad; horns and smaller feet 0.06 long, pectoral feet 0.12 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

Genus 461. Taurospyris,^[79] Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida with two pairs of lateral feet and one pair of lateral horns.

The genus Taurospyris bears only two frontal horns in the coryphal face of the shell, and may therefore be derived from the preceding closely allied Elaphospyris by reduction and loss of the middle or apical horn.

1. Taurospyris cervina, n. sp. (Pl. 95, fig. 12).

Shell nut-shaped, thorny, with deep sagittal stricture and irregular roundish pores; three pairs of larger pores on each side of the ring. Basal plate with four large pores. Two horns cylindrical, curved, widely divergent, about as long as the shell, branched. Four feet of nearly equal length, also cylindrical and curved, divergent, somewhat longer than the shell, in the distal half branched like a deer's antler.

Dimensions.—Shell 0.07 long, 0.11 broad; horns 0.03 long, feet 0.06 long.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms; also fossil in Barbados.

2. Taurospyris bovina, n. sp.

Shell subspherical, smooth, with slight sagittal stricture and small circular pores. Basal plate with six larger pores. Two horns conical, curved, divergent, about as long as the shell. Two pectoral feet very large, twice as long as the shell and as the two thinner tergal feet; all four feet curved, cylindrical, divergent, pointed at the distal end.

Dimensions.—Shell 0.08 long, 0.09 broad; horns and posterior feet 0.1, anterior feet 0.2 long.

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

Genus 462. Therospyris,^[80] Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida with two pairs of lateral feet, without apical horn.

The genus Therospyris has two pairs of lateral feet corresponding to those of the preceding three genera, but differs from them in the complete absence of horns on the coryphal face of the shell.

1. Therospyris canis, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores irregular, roundish. Basal plate with four longer pores. Surface covered with roundish tubercles. Four feet equal, divergent, about as long as the shell, thickened at the distal end, club-shaped, not forked.

Dimensions.—Shell 0.07 long, 0.11 broad; feet 0.09 long.

Habitat.—Fossil in Barbados.

2. Therospyris felis, n. sp. (Pl. 89, fig. 6).

Shell nut-shaped, mammillate, with sharp sagittal stricture. Pores large, irregularly roundish or polygonal, of somewhat different size. Basal plate with four large pores. Surface covered with hemispherical pointed mammillæ. Four feet equal, divergent, half as long as the shell, at the distal end forked, with few small branches.

Dimensions.—Shell 0.1 long, 0.15 broad; feet 0.05 long.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

3. Therospyris leo, n. sp. (Pl. 89, fig. 5).

Shell nearly cubical, papillate, with slight sagittal stricture. Pores irregular, roundish; on each side of the ring three pairs of larger pores (the undermost the largest). Basal plate with two large pores. Surface covered with conical papillæ. Four feet equal, divergent, about as long as the shell, with an external spur in the middle, and irregularly branched spines at the distal end.

Dimensions.—Shell 0.08 long, 0.12 broad; feet 0.09 long.

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

Subfamily 7. Polyspyrida, Haeckel, 1881, Prodromus, p. 442.

Definition.—Zygospyrida polypoda, with numerous descending basal feet (at least seven to nine, usually twelve to sixteen or more).

Genus 463. Petalospyris,^[81] Ehrenberg, 1847, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 54.

Definition.—Zygospyrida with numerous (seven to twelve or more) basal feet and one apical horn.

The genus Petalospyris and the following three genera form together the peculiar subfamily of Polyspyrida, differing from the other Zygospyrida in the multiplication of the radial feet, which descend from the basal face of the shell; they may therefore be also called "Zygospyrida multiradiata," and bear the closest relationship to the Archiphænida (or the "Monocyrtida multiradiata"). They differ, however, from the latter in the presence of the distinct sagittal stricture, characteristic of all Spyroidea. The number of the basal feet, which form a coronet around the margin of the basal plate, is commonly between twelve and sixteen, but often more. Their form is usually flat, lamellar, but often also more or less cylindrical or conical.

Subgenus 1. Petalospyrantha, Haeckel.

Definition.—Basal plate with two large collar pores only, separated by the base of the primary ring.

1. Petalospyris foveolata, Ehrenberg.

Petalospyris foveolata, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 14; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 10.

Shell campanulate, smooth, with distinct sagittal stricture and subregular circular pores. Basal plate with two large collar pores only. Apical horn and the eight feet slender, conical, slightly curved, about as long as the shell; feet somewhat divergent (often seven or nine instead of eight).

Dimensions.—Shell diameter 0.04 to 0.05; length of the horn and the feet 0.04 to 0.05.

Habitat.—Fossil in Barbados.

2. Petalospyris floscula, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture and subregular circular pores. Basal plate with two large triangular pores only. Apical horn slender, conical, twice as long as the shell. Twelve to sixteen feet flattened, leaf-shaped, broad, slightly divergent, as long as the shell, with truncate distal end.

Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.12 long, feet 0.05 to 0.07 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

Subgenus 2. Petalospyrella, Haeckel.

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

3. Petalospyris triomma, n. sp. (Pl. 87, fig. 14).

Shell nut-shaped, tuberculate, with sharp sagittal stricture and irregular roundish pores. Basal plate with three large pores and three alternate smaller. Apical horn stout, conical, half as long as the shell. Twelve to fifteen feet, divergent, curved, pointed, as long as the horn.

Dimensions.—Shell 0.06 long, 0.08 broad; horn and feet 0.03 long.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

4. Petalospyris platyacantha, Ehrenberg.

Petalospyris platyacantha, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 8.

Shell campanulate, smooth, with slight sagittal stricture and small irregular roundish pores. Basal plate with three large pores (?). Apical horn very strong, three-sided pyramidal, twice as long as the shell (its edge is described by Ehrenberg as a "canaliculus.") Feet ten to twelve, flat, triangular, vertical, about as long as the shell.

Dimensions.—Shell 0.04 long, 0.05 broad; 0.07 long, feet 0.03 long.

Habitat.—Fossil in Barbados.

5. Petalospyris corona, Stöhr.

Petalospyris corona, Stöhr, 1880, Palæontogr., vol. xxvi. p. 98, Taf. iii. fig. 13.

Shell nut-shaped, smooth, with slight sagittal stricture and very numerous small circular pores; on each side of the stricture three larger annular pores (the undermost the largest). Basal plate with three large pores only. Apical horn very small, conical. Feet twelve to eighteen, short conical, nearly vertical, shorter than the half shell (in my specimen from Caltanisetta much stouter than in that of Stöhr).

Dimensions.—Shell 0.07 long, 0.09 broad; horn and feet 0.01 to 0.03 long.

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

Subgenus 3. Petalospyrissa, Haeckel.

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

6. Petalospyris octopus, n. sp. (Pl. 87, fig. 11).

Shell nut-shaped, tuberculate, with sharp sagittal stricture and irregular, roundish pores. Basal plate with four larger pores. Horn slender, conical, half as long as the shell. Feet eight, very slender, about three times as long as the shell, subvertical, with outer convex edge and convergent ends.

Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.03 long, feet 0.2 long.

Habitat.—Tropical Atlantic, Station 342, depth 1445 fathoms.

7. Petalospyris eupetala, Ehrenberg.

Petalospyris eupetala, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 4.

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.

Petalospyris argiscus, Ehrenberg, 1875, Abhandl. d. k. Akad. Wiss. Berlin, p. 80, Taf. xxii. figs. 1, 2.

Petalospyris argiscus, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 539, Taf. xxxii. fig. 17, a, b.

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.

Petalospyris diaboliscus, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 12; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. xxii. fig. 3.

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.

Petalospyris arachnoides, Haeckel, 1862, Monogr. d. Radiol., p. 294, Taf. xii. fig. 7.

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.

Ceratospyris pentagona, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 15.

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.

Ceratospyris mülleri, Stöhr, 1880, Palæontogr., vol. xxvi. Taf. iii. fig. 15.

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.

Ceratospyris echinus, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx, fig. 12.

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.

Ceratospyris ramosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 66, Taf. xx. fig. 7.

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

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.

Petalospyris pentas, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 11.

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.

Thamnospyris thamnopodia, Haeckel, 1881, Prodromus, p. 143.

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.

Dictyospyris gigas, Ehrenberg, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xix. fig. 6.

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.

Dictyospyris tridentata, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 10, a, b.

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.

Dictyospyris tristoma, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 9.

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.

Dictyospyris triloba, Ehrenberg, 1876, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 8.

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.

Dictyospyris gigas, Bütschli, 1880, Zeitschr. f. wiss. Zool., vol. xxxvi., p. 539, Taf. xxxii. fig. 14a, 14b.

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.

Dictyospyris fenestra, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 68, Taf. xix. fig. 11.

Shell nearly cubical, smooth, without external sagittal stricture. Internal sagittal ring complete. Pores small, roundish; on each side of the ring two crossed pairs of large, square, equal, annular pores. Basal plate also with four longer pores of nearly equal size.

Dimensions.—Shell 0.05 long, 0.07 broad.

Habitat.—Fossil in Barbados.

9. Dictyospyris tetrastoma, Ehrenberg.

Dictyospyris tetrastoma, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 12.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular, roundish. No larger annular pores. Basal plate with four large ovate collar pores (the two cardinal twice as large as the two jugular pores).

Dimensions.—Shell 0.05 long, 0.07 broad.

Habitat.—Cosmopolitan; Atlantic, Indian, Pacific; also fossil in Barbados and Sicily.

10. Dictyospyris spinulosa, Ehrenberg.

Dictyospyris spinulosa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf. xix. fig. 13.

? Ceratospyris borealis, Bailey, 1856, Amer. Journ. of Science and Arts, vol. xxii. pl. i. fig. 3.

Shell nut-shaped, spinulate, without external stricture, with an internal free sagittal ring. Pores numerous, irregular, roundish; on each side of the ring two pairs of very large square pores. Basal plate with four large collar pores.

Dimensions.—Shell 0.07 long, 0.08 broad.

Habitat.—Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms; also fossil in Barbados.

11. Dictyospyris mammillaris, n. sp. (Pl. 89, figs. 9, 10).

Shell mammillate, nut-shaped, with deep sagittal stricture. Mammillæ of the surface hemispherical, with a conical apex. Pores not numerous, large, roundish. Two pairs of large pores on each side of the ring. Basal plate with four large pores.

Dimensions.—Shell 0.06 long, 0.08 broad.

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

12. Dictyospyris anthophora, n. sp. (Pl. 89, fig. 8).

Shell tuberculate, nut-shaped, nearly cubical, without external sagittal strictures. Pores not numerous, large, polygonally roundish. Bars between them compressed, elevated, with large, campanulate or flower-like tubercles on the nodal points. Basal plate with four large pores.

Dimensions.—Shell 0.07 long, 0.09 broad.

Habitat.—North Atlantic, Station 349, depth 2450 fathoms.

13. Dictyospyris quadriloba, n. sp.

Shell nut-shaped, smooth, with deep sagittal stricture. Pores numerous, small, circular, on each side of the ring three to four times as large as on the lateral sides. Basal plate with four very large collar pores and a circle of twenty to twenty-five very small peripheral pores.

Dimensions.—Shell 0.08 long, 0.11 broad.

Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.

14. Dictyospyris messanensis, J. Müller.

Dictyospyris messanensis, J. Müller, 1858, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 46, Taf. ii. fig. 8.

Dictyospyris messanensis, Haeckel, 1862, Monogr. d. Radiol., p. 291.

Shell nut-shaped, spinulate, with deep sagittal stricture. Pores numerous and small, irregular roundish. No larger annular pores on the sides of the ring. Basal plate with four large, nearly equal, pear-shaped collar pores.

Dimensions.—Shell 0.06 long, 0.08 broad.

Habitat.—Mediterranean; Messina, surface.

Subgenus 4. Dictyospyromma, Haeckel.

Definition.—Basal plate with six or more collar pores.

15. Dictyospyris hexastoma, n. sp.

Shell nut-shaped, tuberculate, with deep sagittal stricture. Pores small, irregular, roundish. Three pairs of larger pores on each side of the ring. Basal plate with six large pores; the middle pair (cardinal) twice as large as the anterior (jugular) and the posterior (cervical).

Dimensions.—Shell 0.08 long, 0.12 broad.

Habitat.—Fossil in Barbados.

16. Dictyospyris enneastoma, n. sp.

Shell ellipsoidal, smooth, without external sagittal stricture, but with an internal free sagittal ring. Pores small and numerous, regular, circular. No larger annular pores. Basal plate with nine pores, three larger interradial alternating with three pairs of adradial.

Dimensions.—Shell 0.07 long, 0.11 broad.

Habitat.—South Pacific, Station 297, depth 1775 fathoms.

17. Dictyospyris polystoma, n. sp.

Shell nut-shaped, mammillate, with distinct sagittal stricture. Pores small and numerous, irregular, on each side of the ring three to five times as large as on the lateral sides. Basal plate with twelve large pores (four central and four alternate pairs of peripheral).

Dimensions.—Shell 0.1 long, 0.14 broad.

Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.

Family LIII. Tholospyrida, n. fam.

(Pl. 87, figs. 7-10; Pl. 89, figs. 1-4; Pl. 95, figs. 14-16).

Definition.—Spyroidea with a galea, but without thorax; the shell being composed of the bilocular cephalis and of an aboral cupola or galea arising from its coryphal face.

The family Tholospyrida differs from the preceding Zygospyrida, its ancestral group, in the development of a galea, i.e., a fenestrated hemispherical or dome-shaped cupola, which covers the upper face of the cephalis like a cap.

Only three species of this family have been hitherto described: Pylospyris (or Spyridobotrys) trinacria, figured in my Monograph (1862), Pylospyris (or Lithopera) denticulata, figured by Ehrenberg (1872), and Lophospyris (or Ceratospyris) acuminata, figured by Hertwig (1879). Fourteen new species have been found in the collection of the Challenger, which we dispose here among five genera. These may be derived from corresponding genera of Zygospyrida by the development of a galea.

The number and disposition of the terminal feet around the basal plate do not vary so much in the Tholospyrida as in the Zygospyrida. We find here only one genus with three feet, Tholospyris (corresponding to Tripospyris); one genus with two lateral feet, Lophospyris (corresponding to Dipospyris); and two genera with numerous feet, the horned Sepalospyris and the hornless Tiarospyris (the former corresponding to Petalospyris, the latter to Gorgospyris). The fifth genus (Pylospyris) has no feet at all, and may be derived from Circospyris among the Zygospyrida.

The cephalis exhibits in the Tholospyrida the same typical structure which we have described above of all Spyroidea (compare p. 1017). The cupola or galea, arising from its upper face, seems to be a secondary production, perhaps caused by an apical growth of the central capsule, or in other cases by descending branches of the apical horn, which cover the apical face of the calymma with protecting network.

Synopsis of the Genera of Tholospyrida.

I. Subfamily Lophospyrida. Two or three basal (cortinar feet). Galea with a horn. Three basal feet (two paired pectoral and an odd caudal), 469. Tholospyris.

Two paired basal (pectoral) feet, 470. Lophospyris.

II. Subfamily Tiarospyrida. Numerous basal feet in a corona (six to nine or more). Galea with a horn, 471. Sepalospyris.

Galea without a horn, 472. Tiarospyris.

III. Subfamily Pylospyrida. No basal feet. Galea with a horn, 473. Pylospyris.

I. Subfamily Lophospyrida. Two or three basal (cortinar feet). Galea with a horn.

Three basal feet (two paired pectoral and an odd caudal),

469. Tholospyris.

Two paired basal (pectoral) feet,

470. Lophospyris.

II. Subfamily Tiarospyrida. Numerous basal feet in a corona (six to nine or more).

Galea with a horn,

471. Sepalospyris.

Galea without a horn,

472. Tiarospyris.

III. Subfamily Pylospyrida. No basal feet.

Galea with a horn,

473. Pylospyris.

Genus 469. Tholospyris,^[87] Haeckel, 1881, Prodromus, p. 441.

Definition.—Tholospyrida with three basal feet and an apical horn.

The genus Tholospyris is probably the common ancestral form of the Tholospyrida, and has arisen from Tripospyris by development of a galea or cupola; this is composed of the apical horn, the lateral branches of which become connected with lateral spines arising from the coryphal face of the cephalis, and of lattice-work developed between the former and the latter. The three descending feet of the basal face are the typical cortinar feet (one odd caudal and two paired pectoral), the same as in the old ancestral genera Cortina, Plagoniscus, Tripospyris, &c.

Subgenus 1. Tholospyrium, Haeckel.

Definition.—Basal feet simple, neither forked nor branched.

1. Tholospyris tripodiscus, n. sp. (Pl. 89, fig. 1).

Shell campanulate, smooth, as broad as long, with deep sagittal stricture. Cephalis compressed, with irregular roundish pores; two or three pairs of larger annular pores on each side of the ring. Basal plate with four large pores. Galea with two very large opposite holes (an occipital and a frontal opening). A slender free perpendicular columella connects the uppermost part of the sagittal ring with the strong three-sided pyramidal apical horn. All three feet of equal length, half as long as the ring, three-sided, prismatic, divergent, with three dentated edges.

Dimensions.—Shell 0.13 diameter, ring 0.08 long, feet 0.05 long.

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

2. Tholospyris fenestrata, n. sp. (Pl. 89, fig. 2).

Shell roundish polyhedral, smooth, with slight sagittal stricture. Cephalis nearly cubical, with irregularly roundish pores; two or three pairs of larger pores on each side of the ring. Basal plate with two very large pores. Galea pyramidal, with two large occipital holes. Columella enclosed in the dorsal wall of the galea, prolonged into an oblique pyramidal spine of the same length. Two pectoral feet pyramidal, nearly vertical and as long as the ring, twice as long as the caudal foot.

Dimensions.—Shell 0.12 diameter, ring 0.07, pectoral feet 0.05 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

3. Tholospyris galeata, n. sp.

Shell helmet-shaped, thorny, with deep sagittal stricture. Cephalis campanulate, with subregular circular pores. Basal plate with three large pores. Galea hemispherical, separated from the cephalis by a sharp horizontal stricture; pores smaller. A slender free columella connects the apex of the ring with the strong conical apical horn, which is half as long as the ring. All three feet of equal length, divergent conical, as long as the horn.

Dimensions.—Shell 0.14 diameter, ring 0.09 long, feet 0.08 long.

Habitat.—Central Pacific, Station 263, depth 2650 fathoms.

Subgenus 2. Tholospyridium, Haeckel.

Definition.—Basal feet forked or branched.

4. Tholospyris ramosa, n. sp. (Pl. 89, fig. 3).

Shell helmet-shaped, smooth, with deep sagittal stricture. Cephalis nearly spherical, with irregularly polygonal pores; four or five pairs of larger annular pores on each side of the strong angular ring. Cupola flat, conical, with two pairs of larger pores. Columella enclosed in its dorsal wall, bearing an irregularly branched horn. Caudal foot short conical, simple. Two pectoral feet half as long as the shell, angular, subvertical, irregularly branched.

Dimensions.—Shell 0.15 diameter, ring 0.1 long, pectoral feet 0.07 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

5. Tholospyris cupola, n. sp. (Pl. 89, fig. 4).

Shell pear-shaped or cupola-shaped, smooth, with slight sagittal stricture. Cephalis not distinctly separated from the galea, as the ring in the uppermost part of the shell-wall becomes obliterated. Pores irregularly polygonal, small and numerous. Basal plate with four large pores. Apical horn and the three divergent feet, irregularly branched; feet nearly as long as the shell, about four times as long as the horn.

Dimensions.—Shell 0.14 diameter, ring 0.1 long, feet 0.12 long.

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

Genus 470. Lophospyris,^[88] Haeckel, 1881, Prodromus, p. 443 (sensu emendato).

Definition.—Tholospyrida with two lateral basal feet and an apical horn.

The genus Lophospyris differs from the preceding Tholospyris, its probable ancestral form, in the absence of the caudal foot, and therefore bears to it the same relation that Dipospyris does to Tripospyris. The two pectoral feet are alone developed and are placed opposite in the frontal plane. Lophospyris may also be derived from Dipospyris by the formation of a galea.

1. Lophospyris dipodiscus, n. sp. (Pl. 95, fig. 14).

Shell ovate, spinulate, with sharp transverse coronal constriction. Cupola hemispherical, half as large as the nut-shaped cephalis. Pores irregularly roundish, much larger on the sagittal constriction. Apical horn pyramidal, about half as long as the shell. Two lateral feet cylindrical, strongly curved, about as long as the shell, with some irregular branches; together forming a nearly complete circle.

Dimensions.—Shell 0.09 long, 0.08 broad; ring 0.04 long, feet 0.08 long.

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

2. Lophospyris acuminata, Haeckel.

Ceratospyris acuminata, R. Hertwig, 1879, Organism. d. Radiol., p. 70, Taf. vii. fig. 2.

Shell campanulate, smooth, without external transverse stricture. Cupola conical, half as long and broad as the nut-shaped cephalis. Pores irregularly roundish, on each side of the sagittal strictures much larger. Basal plate with four large triangular pores. Apical horn slender, prismatic; its outer free part of the same length as the inner columella, and as the two lateral feet, which are curved, shorter than half the ring.

Dimensions.—Shell 0.08 long, 0.09 broad; ring 0.06 long; horn and feet 0.03 long.

Habitat.—Mediterranean, Messina (R. Hertwig).

3. Lophospyris comosa, n. sp.

Shell ovate, spiny, with deep transverse stricture. Cupola large, campanulate, nearly as long and two-thirds as broad as the nut-shaped cephalis. Pores irregular, roundish, of little different size, Basal plate with numerous (eight to twelve) similar pores. Apical horn large, nearly as long as the shell, surrounded by a bunch of smaller divergent spines. Two lateral feet divergent, larger than the shell, cylindrical; at the distal end irregularly branched, at the base surrounded by some smaller spines.

Dimensions.—Shell 0.15 long, 0.11 broad; ring 0.08 long; feet 0.2 long.

Habitat.—Western Tropical Pacific, Station 206, depth 2100 fathoms.

Genus 471. Sepalospyris,^[89] Haeckel, 1881, Prodromus, p. 443.

Definition.—Tholospyrida with numerous basal feet (eight to twelve or more). Galea with a horn.

The genus Sepalospyris has been derived from the similar Petalospyris by development of a galea or cupola on the coryphal face of the cephalis, or from Tholospyris by multiplication of the basal feet. The latter (in the two observed species from twelve to twenty-five) form a regular corona around the basal plate.

1. Sepalospyris platyphylla, n. sp. Pl. 95, fig. 15.

Shell ovate, rough, with sharp transverse stricture. Cupola with delicate network, hemispherical, about two-thirds as long and broad as the nut-shaped thorax. Pores of the latter irregular, roundish; two or three pairs of large pores on each side of the sagittal stricture. Apical horn conical, half as long as the shell. Basal coronet with twelve to fifteen broad, lamellar, truncate, vertical feet, somewhat shorter than the cephalis.

Dimensions.—Shell 0.12 long, 0.13 broad; ring 0.06 long; horn 0.04; feet 0.05 long.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

2. Sepalospyris polyphylla, n. sp.

Shell campanulate, rough, with deep transverse stricture. Cupola hemispherical, about one-third as long and broad as the nut-shaped thorax. Pores irregular, roundish, a little different in size. Apical horn pyramidal, about as long an the shell. Basal coronet with twenty to twenty-five slender, lamellar, pointed, vertical feet, longer than the shell.

Dimensions.—Shell 0.11 long, 0.12 broad; ring 0.07 long; horn 0.1; feet 0.12 to 0.18 long.

Habitat.—Central Pacific, Station 268, depth 2900 fathoms.

Genus 472. Tiarospyris,^[90] Haeckel, 1881, Prodromus, p. 443.

Definition.—Tholospyrida with numerous basal feet (eight to twelve or more). Galea without a horn.

The genus Tiarospyris has probably been derived from the preceding Sepalospyris by reduction and loss of the free apical horn; it therefore bears to it the same relation that the similar Gorgospyris does to Petalospyris.

1. Tiarospyris pervia, n. sp. (Pl. 87, fig. 7).

Shell nut-shaped, smooth, with deep sagittal stricture. Cephalis on the lateral sides with numerous small roundish pores, on each side of the ring with a pair of very large holes. Basal plate with two large collar pores. Cupola flat, cap-shaped, with two large parietal pores above the ring. Coronet with eight conical, slightly divergent feet, about one-fourth as long as the shell.

Dimensions.—Shell 0.08 long, 0.1 broad; ring 0.06 long; feet 0.02 long.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

2. Tiarospyris galea, n. sp.

Shell helmet-shaped, with deep sagittal stricture. Cephalis with irregular, polygonal pores; on each side of the ring two pairs of larger annular pores. Basal plate with four large pores. Cupola high, conical, nearly as long as the cephalis, separated from it by a distinct coronal stricture. Basal coronet with twelve to sixteen slender curved divergent feet, nearly as long as the shell.

Dimensions.—Shell 0.16 long, 0.12 broad; ring 0.1 long; feet 0.15 long.

Habitat.—Central Pacific, Station 265, depth 2900 fathoms.

3. Tiarospyris mitra, n. sp. (Pl. 87, figs. 9, 10).

Shell subspherical, smooth. Cephalis on the lateral sides with small roundish, double-contoured pores, on each side of the ring with three to five pairs of larger pores, each of which is closed by a thin fenestrated lamella (different on the frontal face, fig. 9, and the dorsal face, fig. 10). Cupola flat, cap-shaped, separated by a distinct coronal stricture, with similar pores. Basal coronet with, ten to twelve short conical convergent feet.

Dimensions.—Shell 0.11 long, 0.12 broad; ring 0.04 long; feet 0.02 long.

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

4. Tiarospyris amphora, n. sp. (Pl. 87, fig. 8).

Shell amphora-shaped, in the upper half smooth, in the lower spiny, without external sagittal stricture. Cephalis subspherical with a small number of irregular, large, roundish pores, which are closed by a thin fenestrated lamella. Cupola flat, cap-shaped, with numerous small pores. Base covered with numerous conical divergent feet of different sizes, the largest one-third as long as the shell. Internal sagittal ring ovate, nearly free.

Dimensions.—Shell 0.14 long, 0.13 broad; ring 0.1 long; feet 0.04 long.

Habitat.—South Pacific, Station 285, depth 2375 fathoms.

Genus 473. Pylospyris,^[91] Haeckel, 1881 Prodromus, p. 443.

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

The genus Pylospyris was first known from a Mediterranean species, called by me, in 1862, Spyridobotrys trinacria. As this name was given erroneously, on the supposition of a near relation to the Botryodea (= Polycyrtida), I changed it afterwards to Pylospyris. This genus differs from the other Tholospyrida in the total absence of basal feet, and may therefore be derived either from them by reduction of the feet, or from Dictyospyris by formation of a galea.

1. Pylospyris denticulata, Haeckel.

Lithopera denticulata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 297, Taf. xii. II. fig. 7.

Lithobotrys denticulata, Ehrenberg, 1844, Monatsber. d. Akad. Berlin, p. 203.

Shell spinulate, with slight coronal and deep sagittal constriction, with irregular, roundish pores of variable size. Galea hemispherical, about half as long and broad as the nut-shaped cephalis. No symmetrically disposed larger pores.

Dimensions.—Galea 0.04 long, 0.06 broad; cephalis 0.08 long, 0.1 broad.

Habitat.—Antarctic Ocean, Ehrenberg. (Included in the ice.)

2. Pylospyris trinacria, Haeckel.

Spyridobotrys trinacria, Haeckel, 1862, Monogr. d. Radiol., p. 341, Taf. xii. figs. 8, 9.

Shell tuberculate, with sharp coronal and sagittal stricture. Galea campanulate, with very small circular pores, and a short conical apical horn of the same length. Cephalis nut-shaped, with large, irregular, roundish pores; two pairs of larger annular pores on each side of the sagittal ring, also four larger pores in the basal plate.

Dimensions.—Galea 0.03 long, 0.04 broad; cephalis 0.04 long, 0.07 broad.

Habitat.—Mediterranean, Messina, surface.

3. Pylospyris canariensis, n. sp. (Pl. 95, fig. 16).

Shell rough, with deep coronal and slight sagittal constriction. Galea hemispherical, with numerous small irregular, roundish pores, about half as long as the cephalis, with a slender conical horn of twice the length. Cephalis nut-shaped, with larger roundish pores of very unequal size, three pairs of larger pores on each side of the ring. Basal plate with two larger pores.

Dimensions.—Galea 0.03 long, 0.08 broad; cephalis 0.06 long, 0.11 broad.

Habitat.—North Atlantic, Canary Islands, surface.

Family LIV. Phormospyrida, Haeckel (sensu emendato) (Pl. 83, figs. 13-15; Pl. 95, figs. 17-19).

Definition.—Spyroidea with a thorax, without galea; the shell composed of the bilocular cephalis and of a simple thorax arising from its basal face.

The family Phormospyrida differs from the Zygospyrida, their ancestral group, in the development of a thorax, or a second fenestrated shell-joint, which arises from the lower face of the cephalis. It corresponds, therefore, to the Dicyrtida among the Cyrtoidea, and may perhaps be, wholly or partially, the ancestral group of the latter. When the sagittal ring and the longitudinal constriction of the cephalis disappear, the Phormospyrida pass over into the Dicyrtida.

Only three species of this family have been hitherto known, which were found fossil in Barbados, and described by Ehrenberg (1875) as Lithobotrys stiligera and Petalospyris confluens, and by Bütschli (1882) as Petalospyris anthocyrtoides. Fifteen other species are found in the Challenger collection, which we dispose here among five genera.

Two of these five genera (the horned Acrospyris and the hornless Phormospyris) possess the three typical basal feet of Cortina and Tripospyris, and may be derived from these genera by the development of network between the bases of the feet. The three other genera possess numerous feet, and may be derived in the same way from the Polyspyrida; the apical face differs in the three genera, in Desmospyris it is hornless, in Patagospyris it bears an apical horn, and in Rhodospyris three horns (an apical and two lateral or frontal).

The cephalis in the Phormospyrida exhibits the same typical structure, which we have described above, of all Spyroidea (compare, p. 1017). The thorax or the second joint of the shell arises by reticular connection of the bases of the basal feet, and represents a cylindrical or truncate-conical joint in the polypodal forms, or a three-sided joint in the tripodal forms. The terminal aperture or the mouth of the thorax is constantly open, and surrounded by the free ends of the feet.

I. Subfamily Acrospyrida. Three basal cortinar feet (one odd caudal and two paired pectoral). One apical horn, 474. Acrospyris.

No apical horn, 475. Phormospyris.

II. Subfamily Rhodospyrida. Numerous basal feet in a corona (nine to twelve or more.) One apical horn, 476. Patagospyris.

Three apical horns, 477. Rhodospyris.

No apical horn, 478. Desmospyris.

I. Subfamily Acrospyrida. Three basal cortinar feet (one odd caudal and two paired pectoral).

One apical horn,

474. Acrospyris.

No apical horn,

475. Phormospyris.

II. Subfamily Rhodospyrida. Numerous basal feet in a corona (nine to twelve or more.)

One apical horn,

476. Patagospyris.

Three apical horns,

477. Rhodospyris.

No apical horn,

478. Desmospyris.

Subfamily 1. Acrospyrida, Haeckel, 1881, Prodromus, p. 441 (sensu emendato).

Definition.—Phormospyrida with three basal feet (an odd caudal and two paired pectoral).

Genus 474. Acrospyris,^[92] Haeckel, 1881, Prodromus, p. 441.

Definition.—Phormospyrida with three basal feet and one apical horn.

The genus Acrospyris is probably the oldest and most primitive among the Phormospyrida, perhaps the original ancestral form of this family. It has been derived from Tripospyris by the development of lattice-work between the three basal feet, forming a second joint or thorax. It has also therefore a close relation to the simplest forms of the triradiate Dicyrtida: Dictyophimus, Clathrocanium, &c. It differs from these in the distinct sagittal constriction of the cephalis, which divides it into two lateral loculi.

1. Acrospyris clathrocanium, n. sp. (Pl. 95, fig. 17).

Shell tuberculate, with distinct collar and deep sagittal stricture. Cephalis nut-shaped, with numerous irregular, roundish pores; three pairs of larger annular pores on each side of the ring. Basal plate with four larger pores (two major cardinal and two minor jugular pores). Apical horn slender, pyramidal, curved, about as long as the shell, with three recurved short spines. Thorax three-sided, about twice as large as the cephalis, with three large basal holes and a broad riband with numerous smaller holes; three ribs between them stout, pyramidal, strongly curved, prolonged into three convergent crescentic feet.

Dimensions.—Cephalis 0.08 long, 0.11 broad; thorax 0.14 long, 0.16 broad.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

2. Acrospyris dictyophimus, n. sp.

Shell smooth. Cephalis and thorax of nearly the same structure and form as in the preceding species; it differs from the latter in the shape of the three stout basal feet, which are straight, much longer than the thorax, divergent, and at the broader base irregularly fenestrated, without three larger holes.

Dimensions.—Cephalis 0.05 long, 0.08 broad; thorax 0.07 long, 0.12 broad.

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

3. Acrospyris pyramidalis, n. sp.

Shell three-sided pyramidal, with slight collar stricture. Cephalis campanulate, with deep sagittal stricture and stout ring, armed with a strong pyramidal horn of the same length. Thorax shorter and broader, truncate. Pores irregular, roundish, scarce. Three feet divergent, three-sided pyramidal, as long as the cephalis.

Dimensions.—Cephalis 0.05 long, 0.06 broad; thorax 0.02 long, 0.08 broad.

Habitat.—Fossil in Barbados.

4. Acrospyris macrocephala, n. sp.

Shell spinulate, with deep sagittal and very deep collar stricture. Cephalis very large, nut-shaped, twice as long and broad as the small, truncate, pyramidal thorax. Pores irregular, roundish. Horn spindle-shaped, nearly as long as the cephalis; the three divergent feet are of the same form and size as the horn, and arise as three ribs from the deep collar stricture.

Dimensions.—Cephalis 0.1 long, 0.15 broad; thorax 0.05 long, 0.09 broad.

Habitat.—Fossil in Barbados.

5. Acrospyris fragilis, n. sp.

Shell very thin-walled and fragile, with deep sagittal and collar strictures. Pores very small and numerous, circular. Cephalis nut-shaped, nearly spherical, with a slender bristle-shaped horn of the same length. Basal stricture with two large collar pores only (luminella). Thorax nearly three-sided prismatic, longer than the cephalis, with three parallel ribs, prolonged into three slender, long, bristle-shaped feet.

Dimensions.—Cephalis 0.05 long, 0.06 broad; thorax 0.08 long, 0.06 broad.

Habitat.—North Pacific, Station 244, surface.

Genus 475. Phormospyris,^[93] Haeckel, 1881, Prodromus, p. 442 (sensu emendato).

Definition.—Phormospyrida with three basal feet, without apical horn.

The genus Phormospyris has been derived from Acrospyris, its ancestral form, by reduction and loss of the apical horn; it therefore bears to the latter the same relation that Tristylospyris has to the ancestral Tripospyris.

1. Phormospyris tricostata, n. sp. (Pl. 83, fig. 15).

Cephalis nut-shaped, thorny, with deep sagittal and collar strictures, half as large as the pyramidal thorax. Mouth of the latter dilated and ciliated, twice as broad as the cephalis. Pores irregular, polygonal, with thin bars. Three cylindrical, straight, divergent ribs descend in the wall of the thorax, and are prolonged over the mouth into three short conical teeth.

Dimensions.—Cephalis 0.06 long, 0.09 broad; thorns 0.08 long, 0.16 broad.

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

2. Phormospyris tridentata, n. sp. (Pl. 95, fig. 18).

Cephalis nut-shaped, with deep sagittal and collar strictures, about twice as large as the thorax. Mouth of the latter half as broad as the cephalis. Pores very small and numerous, subregular, circular. Collar plate with four large triangular pores. In the wall of the thorax three vertical prismatic ribs descend, which are prolonged over the mouth into three parallel feet of the same length.

Dimensions.—Cephalis 0.06 long, 0.08 broad; thorns 0.04 long, 0.06 broad.

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

3. Phormospyris trifoliata, n. sp.

Cephalis nut-shaped, with deep sagittal and collar strictures, smaller than the thorax. Mouth of the latter nearly as broad as the cephalis. Pores circular, double-contoured, larger in the thorax than in the cephalis. The thorax has no lateral ribs, but bears around the mouth three large triangular lamellar terminal feet.

Dimensions.—Cephalis 0.04 long, 0.05 broad; thorax 0.06 long, 0.05 broad.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

Subfamily 2. Rhodospyrida, Haeckel.

Definition.—Phormospyrida with a corona of numerous (nine to twelve or more) basal feet.

Genus 476. Patagospyris,^[94] Haeckel, 1881, Prodromus, p. 443.

Definition.—Phormospyrida with numerous basal feet (nine to twelve or more) and an apical horn.

The genus Patagospyris and the two following closely allied genera differ from the two preceding tripodal genera in the multiplication of the basal feet, and therefore have to the latter the same relation that the Polyspyrida (Petalospyris) bear to the Tripospyrida (Tripospyris). When the numerous basal feet of Petalospyris become connected by lattice-work, Patagospyris arises.

1. Patagospyris confluens, Haeckel.

Petalospyris confluens, Ehrenberg, 1885, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. xxii. fig. 5.

Shell tuberculate, with distinct sagittal and collar strictures. Pores irregular, roundish. Cephalis nut-shaped, larger than the short truncate thorax. Horn conical, shorter than the cephalis. Peristome with a coronet of twelve to fifteen short triangular feet, which are parallel and vertical, slightly curved and shorter than the thorax.

Dimensions.—Cephalis 0.05 long, 0.07 broad; thorax 0.03 long, 0.07 broad.

Habitat.—Fossil in Barbadoes.

2. Patagospyris lanceolata, n. sp.

Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis subspherical, about as large as the truncate subcylindrical thorax. Horn spindle-shaped, about as long as the cephalis. Peristome with a coronet of fifteen to twenty divergent lanceolate lamellar feet, longer than the thorax.

Dimensions.—Cephalis 0.08 long, 0.09 broad; thorax 0.07 long, 0.07 broad.

Habitat.—Fossil in Barbados.

3. Patagospyris stiligera, Haeckel.

Lithobotrys stiligera, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 76, Taf. iii. fig. 17.

Shell smooth, hyaline, with deep sagittal and collar strictures. Pores very small and few. Cephalis nut-shaped, bilobed, of the same breadth as the cylindrical thorax. Horn conical, about as long as the cephalis. Peristome with a coronet of six to nine broad lamellar feet (in Ehrenberg's figure broken off).

Dimensions.—Cephalis 0.04 to 0.05 diameter; thorax 0.06 long, 0.05 broad.

Habitat.—Fossil in Barbados.

4. Patagospyris anthocyrtis, n. sp. (Pl. 95, fig. 19).

Shell smooth, with deep sagittal and deep collar strictures. Pores irregular, roundish, of various sizes, numerous. Cephalis nut-shaped, with two inflated bosoms, about twice as broad as the short cylindrical thorax. Horn stout, pyramidal, about as long as the cephalis. Peristome with a coronet of fifteen to twenty parallel and vertical triangular lamellar feet, nearly as long as the thorax.

Dimensions.—Cephalis 0.05 long, 0.1 broad; thorax 0.04 long, 0.06 broad.

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

Genus 477. Rhodospyris,^[95] Haeckel, 1881, Prodromus, p. 443.

Definition.—Phormospyrida with numerous basal feet (nine to twelve or more), and with three coryphal horns.

The genus Rhodospyris differs from the preceding Patagospyris in the development of three coryphal horns (one odd middle apical horn, and two paired frontal horns on each of its sides), and therefore bears the same relation to the latter that the similar Anthospyris does to Petalospyris. When the numerous basal feet of Anthospyris become connected by lattice-work, Rhodospyris arises.

1. Rhodospyris tricornis, n. sp. (Pl. 83, fig. 13).

Cephalis nut-shaped, with deep sagittal stricture, and three short apical horns of half its length; the middle odd horn is straight, the two paired lateral horns are curved outwards. Thorax somewhat larger than the cephalis, dilated around the wide open mouth, with a coronet of twenty-five to thirty slender basal feet, which are slightly curved and convergent, about as long as the thorax. Pores small, numerous and circular.

Dimensions.—Cephalis 0.05 long, 0.07 broad; thorax 0.06 long, 0.08 broad; horns 0.02 long, feet 0.06 long.

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

2. Rhodospyris triceros, n. sp.

Cephalis nut-shaped, with deep sagittal and deep collar stricture, and with three stout divergent horns of nearly equal length. Thorax cylindrical, twice as long as the cephalis, and of the same breadth, with a coronet of twelve to sixteen broad, lamellar, rectangular, perpendicular feet around the mouth, about as long as the cephalis. Pores rather large, subregular, circular.

Dimensions.—Cephalis 0.06 long, 0.08 broad; thorax 0.12 long, 0.09 broad.

Habitat.—Indian Ocean, Singapore (Trebing), surface.

Genus 478. Desmospyris,^[96] Haeckel, 1881, Prodromus, p. 443.

Definition.—Phormospyrida with numerous basal feet (nine to twelve or more), without a coryphal horn.

The genus Desmospyris differs from the two preceding polypodal genera in the complete absence of horns on the coryphal face of the cephalis. It therefore corresponds to Gorgospyris among the Zygocyrtida, and arises when the numerous basal feet of the latter become connected by lattice-work.

1. Desmospyris mammillata, n. sp. (Pl. 83, fig. 14).

Shell mammillate, with deep sagittal and slight collar constriction. Pores irregular, roundish. Cephalis nut-shaped, larger than the inversely conical thorax, and twice as broad as the constricted mouth. Coronet of the peristome with twelve to fifteen short conical convergent feet, shorter than half the thorax.

Dimensions.—Cephalis 0.06 long, 0.09 broad; thorax 0.04 long, 0.06 broad.

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

2. Desmospyris cyrtocolpos, n. sp.

Shell smooth, with deep sagittal and collar strictures. Pores subregular, circular, double-contoured, very small and numerous. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with eighteen to twenty-four slender, irregular, pointed, convergent feet, about twice as long as the thorax.

Dimensions.—Cephalis 0.08 long, 0.12 broad; thorax 0.04 long, 0.1 broad.

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

3. Desmospyris anthocyrtoides, Haeckel.

Petalospyris anthocyrtoides, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. pp. 533, 539, Taf. xxxii. fig. 19, a-c.

Shell tuberculate, with slight sagittal and sharp collar strictures. Pores subregular, circular. Cephalis nut-shaped, larger than the short truncate thorax. Coronet with fifteen to twenty short conical, parallel and vertical feet, about as long as the thorax.

Dimensions.—Cephalis 0.06 long, 0.09 broad; thorax 0.02 long, 0.07 broad.

Habitat.—Fossil in Barbados.

4. Desmospyris carpocanium, n. sp.

Shell smooth, with slight sagittal and slight collar strictures. Pores subregular, circular, small and numerous. Cephalis campanulate, smaller than the ovate thorax. Coronet with fifteen to twenty irregular lamellar feet, which are longer than the thorax, pointed, nearly vertical and parallel.

Dimensions.—Cephalis 0.05 long, 0.08 broad; thorax 0.07 long, 0.1 broad.

Habitat.—South Pacific, Station 298, depth 2225 fathoms.

Family LV. Androspyrida, n. fam. (Pl. 88-90).

Definition.—Spyroidea with galea and thorax; the shell composed of a bilocular cephalis and of two secondary joints, a galea arising from its upper face, and a thorax arising from its lower face.

The family Androspyrida differs from the three preceding families of Spyroidea in the three-jointed shell, in which the galea of the Tholospyrida and the thorax of the Phormospyrida are combined; it may therefore be derived from the latter by development of a galea, or from the former by formation of a thorax. The common ancestral group of these three families is probably the Zygospyrida. But it may be that a part of the Androspyrida has originated directly from the Stephoidea.

Two species only of this family were hitherto known, Amphispyris reticulata (figured, in 1872, by Ehrenberg, as Dictyospyris) and Sphærospyris sphæra (described, in 1882, by Bütschli, as Dictyospyris). Thirty new species were found in the collection of the Challenger, and are here disposed in seven genera. But perhaps these may represent three different families, which we here enumerate as subfamilies; the Lamprospyrida, Perispyrida, and Nephrospyrida.

The Lamprospyrida, the first subfamily, are tripodal Spyroidea with galea and thorax; they may therefore be regarded as a combination of Tholospyris and Acrospyris. In the simpler form, Androspyris (Pl. 83, fig. 8), the network of the shell is simple, and allows a very clear recognition of the internal structure. In the splendid Lamprospyris, derived from it (Pl. 89, figs. 13, 14) the delicate network is more or less spongy. The large apical horn is branched and fenestrated in the latter and simple in the former.

The Perispyrida, the second subfamily, possess no free apophyses, but a three-jointed shell with two distinct transverse strictures, an upper mitral and a lower collar stricture. The network of this shell is incomplete in Amphispyris (Pl. 88, figs. 2-7), being developed only in the frontal or lateral perimeter, thus making it probable that this subfamily may have arisen directly from the Tympanida (Toxarium, Pl. 88, fig. 1; Pl. 93, figs. 18-20). The network of Tricolospyris (Pl. 88, figs. 8-11) is complete, of another shape in the cephalis than in the galea and thorax; it is doubled or spongy in Perispyris (Pl. 88, figs. 12, 13).

The Nephrospyrida, the third subfamily, contains two very different genera only, each of which may represent a separate family. Sphærospyris (Pl. 83, fig. 4) possesses a spherical or subspherical lattice-shell, the central part of which includes a sagittal ring, connected with the inner face of the sphere by a number of paired apophyses, corresponding to those of Lithocircus; it may be easily confounded with some Sphæroidea (Carposphæra), but the enclosed ring leaves no doubt as to its true origin. Nephrospyris (Pl. 90) has a flat discoidal shell of considerable size, usually kidney-shaped or cordate, with a deep sagittal incision at the base, indicating the region where the pseudopodia are protruded from the porochora. The violin-shaped central capsule has two large lateral lobes on each side of the including sagittal ring, and the transverse nucleus is perpendicular to its sagittal plane (Pl. 90, figs. 7, 10). Sphærocircus as well as Nephrospyris have probably arisen independently from the Stephanida.

Synopsis of the Genera of Androspyrida.

I. Subfamily Lamprospyrida. Three free basal feet. Lattice-work simple, not spongy. Apical horn usually simple, not fenestrated, 479. Androspyris.

Lattice-work wholly or partly spongy. Apical horn usually branched and fenestrated, 480. Lamprospyris.

II. Subfamily Perispyrida. No free basal feet. Shell three-jointed. Shell with two transverse coronal strictures (one superior mitral and one inferior collar stricture). Lattice-work only complete in the frontal ring, 481. Amphispyris.

Lattice-work complete on all sides, 482. Tricolospyris.

Lattice-work double or spongy, 483. Perispyris.

III. Subfamily Nephrospyrida. No free basal feet. Shell spherical or discoidal. Shell without external transverse stricture. Shell spherical or subspherical, 484. Sphærospyris.

Shell discoidal, kidney-shaped or subcircular, 485. Nephrospyris.

I. Subfamily Lamprospyrida. Three free basal feet.

Lattice-work simple, not spongy.

Apical horn usually simple, not fenestrated,

479. Androspyris.

Lattice-work wholly or partly spongy.

Apical horn usually branched and fenestrated,

480. Lamprospyris.

II. Subfamily Perispyrida. No free basal feet. Shell three-jointed.

Shell with two transverse coronal strictures (one superior mitral and one inferior collar stricture).

Lattice-work only complete in the frontal ring,

481. Amphispyris.

Lattice-work complete on all sides,

482. Tricolospyris.

Lattice-work double or spongy,

483. Perispyris.

III. Subfamily Nephrospyrida. No free basal feet. Shell spherical or discoidal.

Shell without external transverse stricture.

Shell spherical or subspherical,

484. Sphærospyris.

Shell discoidal, kidney-shaped or subcircular,

485. Nephrospyris.

Subfamily 1. Lamprospyrida, Haeckel.

Definition.—Androspyrida with three free basal feet (an odd posterior caudal foot and two paired anterior pectoral feet).

Genus 479. Androspyris,^[97] n. gen.

Definition.—Androspyrida with three free basal feet and a simple apical horn; lattice-work of the three-jointed shell simple, not spongy.

The genus Androspyris is probably the most original form of the Androspyrida, and represents, together with the following Lamprospyris, the subfamily of Lamprospyrida, which always possess three free basal feet, an odd posterior or caudal foot, and two paired anterior or pectoral feet. It may be derived either from Acrospyris by development of a cupola, or from Tholospyris by development of a thorax; the common ancestral form of these three typical genera is, no doubt, Tripospyris. Some species of Androspyris reach a considerable size and are distinguished by a peculiar external form resembling somewhat a human figure.

1. Androspyris homunculus, n. sp.

Shell thorny, with two deep transverse constrictions and irregular polygonal pores. Galea subspherical, with a strong pyramidal oblique horn, about two-thirds as large as the cephalis, which has the form of a human thorax, includes a strong ovate sagittal ring, and bears on each side a stronger lateral spine. Thorax short and broad, prolonged into three latticed divergent feet; the two lateral (pectoral) feet are like the legs of a human body, and are twice as long as the cephalis and as the tail-like caudal feet. (The whole shell exhibits a curious similarity to a human figure, more than in the following nearly allied species.)

Dimensions.—Length of the shell (including horn and feet) 0.4, breadth 0.1 to 0.15.

Habitat.—Central Pacific, Station 273, depth 2350 fathoms.

2. Androspyris anthropiscus, n. sp. (Pl. 83, fig. 8).

Shell rough, with two distinct transverse constrictions and irregular polygonal pores. Galea ovate, with a slender conical oblique horn, about as large as the cephalis, which exhibits a deep longitudinal furrow in the sagittal dorsal line. Thorax half as long, prolonged into three short latticed feet; the terminal spines of the two lateral feet are vertical and parallel, that of the caudal foot larger, directed obliquely backwards.

Dimensions.—Length of the shell (including horn and feet) 0.35, breadth 0.1 to 0.12.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

3. Androspyris pithecus, n. sp. (Pl. 95, fig. 20).

Shell smooth, with two slight transverse constrictions. Galea conical, with a short conical horn, longer than the nut-shaped cephalis. Thorax with three nearly vertical and parallel feet of equal length. Pores in the galea and thorax very small and numerous, circular, in the cephalis much larger, irregular, roundish.

Dimensions.—Length of the shell (including horns and feet) 0.25, breadth 0.06 to 0.08.

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

4. Androspyris aptenodytes, n. sp.

Shell smooth, with two slight transverse constrictions and irregular, roundish pores. Galea hemispherical, with a short conical horn, about as large as the roundish cephalis and half as large as the ovate thorax. The three feet arise immediately beyond the collar stricture, are equal, divergent, curved, about as long as the cephalis, and are not terminal (as in the three preceding species), but lateral appendages of the thorax.

Dimensions.—Length of the shell 0.2, breadth 0.05 to 0.07.

Habitat.—Antarctic Ocean, Station 157, depth 1950 fathoms.

Genus 480. Lamprospyris,^[98] Haeckel, 1881, Prodromus, p. 447.

Definition.—Androspyrida with three free basal feet and a fenestrated apical horn; lattice-work of the three-jointed shell wholly or partly spongy.

The genus Lamprospyris differs from the preceding Androspyris, its ancestral form, mainly in the higher development of the lattice-work of the large shell. Whilst this in the latter genus is a simple lattice-plate, it here becomes more or less spongy, and sometimes forms a very dense and delicate wickerwork. The apical horn and the three basal feet are commonly also fenestrated. The two annular strictures, which separate the cephalis from the conical cupola and the inflated thorax, are commonly not so distinct as in the preceding genus. Some species belong to the largest Spyroidea and reach more than half a millimetre in length.

1. Lamprospyris darwinii, n. sp. (Pl. 89, fig. 13).

Shell nearly pear-shaped, with two distinct annular strictures, and uneven papillate surface. The total length is equal to twice the greatest breadth, and to seven times the length of the ring. Apical horn free, irregularly branched and fenestrated, as long as the included columella beyond it. The three diverging feet are strongly curved, S-shaped, and completely included by loose lattice-work. In the middle of their length they give off a simple strong lateral branch. The loose arachnoidal lattice-work is rather equally developed.

Dimensions.—Length of the entire shell (including the apophyses) 0.5, greatest breadth 0.25, ring 0.07 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

2. Lamprospyris lyellii, n. sp.

Shell slender, pear-shaped, very similar to the preceding species, but differing in the following characters—the branched horn is much larger and twice as long as the columella; the two annular transverse strictures (separating the three joints) are deeper. The free internal branches of the three included feet are forked. Lattice-work looser than in the preceding species.

Dimensions.—Length of the entire shell 0.6, breadth 0.2, ring 0.09 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

3. Lamprospyris huxleyi, n. sp. (Pl. 89, fig. 14).

Shell ovate, spiny, with two slight annular transverse strictures; their length equal to one and a half times the breadth, and up to seven times the length of the ring. Apical horn quite included by the loose lattice-work of the large conical cupola, which is as long as the cephalis and thorax together. The three slender feet are also included in the lattice-work and only one-third as long as the shell, nearly vertical. Lattice-work much denser than in the two preceding species.

Dimensions.—Length of the shell 0.4, breadth 0.26, ring 0.06 long.

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

4. Lamprospyris hookeri, n. sp.

Shell ovato-conical, very similar to the preceding species, but smooth, not spiny. The apical horn and the three feet are much longer, not included in the network, but freely prominent, half as long as the shell and nearly vertical, parallel. The arachnoidal lattice-work is much denser in the middle third (cephalis) than in the upper third (cupola) of the lower third (thorax).

Dimensions.—Length of the shell (without appendages) 0.45, breadth 0.3, ring 0.08 long.

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

5. Lamprospyris spenceri, n. sp.

Shell slender, ovate, very similar to the preceding species; differing from it in the larger cupola, which is as long as the cephalis and thorax together. The three feet are much shorter and weaker, more divergent. This differs from all four preceding species in the possession of a large double apical horn; the two horns are strong, pyramidal, straight, strongly divergent, and as long as the cupola.

Dimensions.—Length of the shell (without the appendages) 0.3, breadth 0.2, ring 0.05 long.

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

Subfamily 2. Perispyrida, Haeckel, 1881, Prodromus, p. 443.

Definition.—Androspyrida without free basal feet, with three distinct joints separated by two parallel transverse strictures.

Genus 481. Amphispyris,^[99] Haeckel, 1881, Prodromus, p. 444.

Definition.—Androspyrida without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell only complete in the frontal ring, with large open holes on the ventral and dorsal face.

The genus Amphispyris and the two following genera arising from it, represent together the peculiar small subfamily of Perispyrida. This may have originated directly from Toxarium (family Tympanida, Pl. 88, fig. 1; Pl. 93, figs. 18-20), the large holes between its arches and rings becoming filled up by lattice-work; in Amphispyris this intercalated network remains incomplete on the ventral and dorsal faces, whilst in Tricolospyris it becomes complete, and in Perispyris spongy.

Subgenus 1. Amphispyrium, Haeckel.

Definition.—On each side of the ring-plane three pairs of large annular meshes; no middle zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxillary ring).

1. Amphispyris thorax, n. sp. (Pl. 88, fig. 4).

Shell thorax-shaped, as long as broad, with a deep sternal incision and two slight transverse strictures. On each side of the ring-plane three pairs of large, irregular, annular holes of nearly equal size, the middle holes nearly half as broad as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle narrow, with few small roundish meshes.

Dimensions.—Shell 0.17 long, 0.17 broad, ring 0.06 long.

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

2. Amphispyris quadrigemina, n. sp. (Pl. 88, fig. 6).

Shell shaped like the "corpora quadrigemina cerebralia," with two deep crossed strictures, a coronal transverse stricture and a sagittal sternal stricture. On each side of the ring plane three pairs of large, irregular, annular, double holes, the middle holes larger than the upper and lower holes, and about one-fourth as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral lattice-girdle broad, with numerous small meshes.

Dimensions.—Shell 0.13 long, 0.16 broad, ring 0.07 long.

Habitat.—Central Pacific, Station 266, depth 2750 fathoms.

3. Amphispyris reticulata, Haeckel.

Dictyospyris reticulata, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 289, Taf. x. fig. 19.

Shell thorax-shaped, one and one-fifth times as long as broad, with a deep sternal incision and two distinct transverse strictures. On each side of the ring-plane three pairs of large annular holes of nearly equal size, about one-third as long as the shell. No zygomatic bars between the orbital and maxillary bars. Lateral girdle narrow, with few large polygonal meshes.

Dimensions.—Shell 0.18 long, 0.15 broad.

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

Subgenus 2. Amphispyridium, Haeckel.

Definition.—On each side of the ring-plane four pairs of larger annular meshes; a middle horizontal zygomatic ring is developed between the two tympanic transverse rings (superior orbital and inferior maxillary ring).

4. Amphispyris sternalis, n. sp. (Pl. 88, fig. 2).

Shell thorax-shaped, one and one-fifth times as long as broad, with deep sternal incision and two distinct transverse (tympanic) strictures. On each side of the ring-plane four pairs of large irregular, annular holes; the fourth (inferior or buccal) pair is the longest. The middle of the sagittal ring is crossed by horizontal zygomatic bars (between the ascending orbital and the descending maxillary bars). Lateral lattice-girdle narrow, with few large meshes.

Dimensions.—Shell 0.24 long, 0.2 broad; ring 0.09 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

5. Amphispyris subquadrata, n. sp. (Pl. 88, fig. 5).

Shell compressed, nearly square, spiny, with slight sternal incision and two distinct transverse strictures. Similar to the preceding species; four pairs of irregular annular pores of nearly equal size. Zygomatic ring complete. Lateral lattice-girdle narrow, with few large meshes.

Dimensions.—Shell 0.14 long, 0.12 broad; ring 0.06 long.

Habitat.—Central Pacific, Station 285, depth 2275 fathoms.

6. Amphispyris costata, n. sp. (Pl. 88, fig. 3).

Shell compressed, nearly square, with slight sternal incision and two obliterated transverse strictures. Similar to the two preceding species; with four pairs of large annular pores, the two middle of which (the orbital and nasal holes) are much larger than the superior (frontal) and inferior (oral) holes. Zygomatic ring incomplete. Lateral lattice-girdle broad, with very numerous, small, irregular, polygonal pores.

Dimensions.—Shell 0.2 long, 0.16 broad; ring 0.07 long.

Habitat.—North Pacific, Station 244, depth 2900 fathoms.

7. Amphispyris toxarium, n. sp. (Pl. 88, fig. 7).

Shell inflated, with deep sternal incision and two distinct transverse strictures. Similar to the preceding species, but with deeper constriction and looser lattice-work. Four pairs of large, irregular, annular pores, the central two of which are much larger. Zygomatic ring complete. Lateral girdle broad, with irregular pores of very different size.

Dimensions.—Shell 0.2 long, 0.14 broad; ring 0.09 long.

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

Genus 482. Tricolospyris,^[100] Haeckel, 1881, Prodromus, p. 443.

Definition.—Androspyrida without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell complete, simple.

The genus Tricolospyris has arisen from the preceding Amphispyris, its ancestral form, by development of lattice-work which completely closes the large open holes remaining on the ventral and dorsal faces of the latter.

1. Tricolospyris kantiana, n. sp. (Pl. 88, fig. 10).

Shell smooth, one and a half times as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, of nearly equal size. Cupola and thorax hemispherical, of about the same size and form, with numerous and small, double-contoured, roundish pores.

Dimensions.—Shell 0.12 long, 0.08 broad; ring 0.04 long.

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

2. Tricolospyris leibnitziana, n. sp. (Pl. 88, fig. 9).

Shell spiny, twice as long as broad, with two deep transverse strictures. Pores of the cephalis large, roundish, polygonally framed, of very different size; two middle transverse rows of smaller pores enclosed between a superior and an inferior row of very large pores. Cupola and thorax hemispherical, about equal, with much smaller and very numerous roundish pores.

Dimensions.—Shell 0.15 long, 0.07 broad; ring 0.06 long.

Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.

3. Tricolospyris baconiana, n. sp. (Pl. 88, fig. 8).

Shell rough, twice as long as broad, with two sharp strictures. Pores of the cephalis large, very irregular, partly lobated. Cupola hemispherical, smaller than the campanulate thorax, both with smaller irregular pores.

Dimensions.—Shell 0.15 long, 0.08 broad; ring 0.06 long.

Habitat.—Western Tropical Pacific, Station 215, depth 2500 fathoms.

4. Tricolospyris newtoniana, n. sp. (Pl. 88, fig. 11).

Shell spiny, slender, three times as long as broad, with two distinct strictures. Pores of the cephalis very large, irregular. Cupola hemispherical, only one-third as long as the slender inversely conical abdomen, both with irregular, much smaller pores.

Dimensions.—Shell 0.22 long, 0.08 broad; ring 0.05 long.

Habitat.—Western Tropical Pacific, Station 206, depth 2100 fathoms.

Genus 483. Perispyris,^[101] Haeckel, 1881, Prodromus, p. 444.

Definition.—Androspyrida without free basal feet, with three distinct joints, separated by two transverse strictures; lattice-work of the shell double or spongy.

The genus Perispyris differs from the preceding Tricolospyris, its ancestral form, in the development of a secondary outer shell, which encloses the inner primary one either like an enveloping cortical shell or like a spongy veil. This is produced by the concrescence of meeting branches, which arise from spines of the inner shell.