Synopsis of the Genera of Zygospyrida.

Subfamily 1. Tripospyrida, Haeckel, 1881, Prodromus, p. 441.

Definition.—Zygospyrida tripoda, with three descending basal feet (the same as in Cortina, an odd posterior or caudal foot and two paired anterior or pectoral feet).

Genus 441. Tripospyris,^[59] Haeckel, 1881, Prodromus, p. 441.

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

The genus Tripospyris (Pl. 84, figs. 1-7) is in the large group of Spyroidea probably the most original and typical form, from which, as a common ancestral form, all other genera of this polymorphous suborder may be derived. The shell is usually shaped like a nut or thorax, and exhibits two paired lateral chambers, which are separated by a distinct sagittal ring and a slighter or deeper sagittal constriction. The dorsal rod of the ring is prolonged at the upper pole into an ascending apical horn, at the lower pole into a descending caudal foot, whilst two paired pectoral or lateral feet arise from the anterior pole of the basal rod. These three divergent basal feet and the apical horn are the same four typical radial spines which we have encountered already in Plagoniscus (Plagonida), in Plectaniscus (Plectanida), in Cortina (Stephanida), and in Cortiniscus (Semantida). Compare above, p. 891. From all these Plectellaria, Tripospyris differs in the development of a complete bilocular lattice-shell, having the characters of the true Spyroidea. The numerous species of this genus may be placed in different subgenera, according to the different number of collar pores or cortinar pores in the basal plate (two, three, four, six, or more). These differences are very important, however difficult to make out; the following system therefore is a provisional one, and requires further accurate observations.

Subgenus 1. Tripospyrantha, Haeckel.

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

1. Tripospyris cortina, n. sp. (Pl. 95, fig. 1).

Shell ovate, smooth, about as long as broad, with slight ovate sagittal stricture, and broad primary ring in its wall. Basal plate with two large kidney-shaped collar pores only (cardinal pores). Facial and occipital plates each with two pairs of large annular pores, and ten to twelve pairs of small lateral pores. Apical horn and the three basal feet of equal length, one and a half times as long as the shell, three-sided prismatic, straight, divergent.

Dimensions.—Shell 0.08 long, 0.09 broad; horn and feet 0.15 long.

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

2. Tripospyris cortiniscus, n. sp. (Pl. 84, fig. 6).

Shell ovate, smooth, one and a third times as long as broad, with sharp ovate sagittal stricture and broad primary ring. Basal plate with two large cardinal pores only. Occipital plate with two pairs of very large pores; facial plate and lateral sides with numerous smaller irregular roundish pores. Apical horn small, conical, curved, half as long as the three basal feet, which are club-shaped and three-edged, with thinner bases and half as long as the shell, strongly divergent.

Dimensions.—Shell 0.12 long, 0.09 broad; horn 0.03 long, feet 0.06 long.

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

3. Tripospyris semantis, n. sp. (Pl. 84, figs. 2, 3).

Shell subspherical, smooth, somewhat broader than long, with slight sagittal stricture and subcircular parietal primary ring. Basal plate with two large semicircular cardinal pores. Facial and occipital plate each with two pairs of large annular pores and an odd large subapical pore; lateral sides with very numerous small roundish pores. Apical horn and caudal foot club-shaped, half as long as the shell, angular, simple; the two pectoral feet somewhat longer, nearly vertical, and at the distal end with a small incision, nearly forked.

Dimensions.—Shell 0.1 long, 0.12 broad; horn and feet 0.05 to 0.07 long.

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

4. Tripospyris diomma, n. sp. (Pl. 84, fig. 5).

Shell thorax-shaped, smooth, twice as broad as long, with deep sagittal stricture, two vaulted ovate bosoms and smaller ovate internal primary ring. Basal plate with two large ovate cardinal pores. Facial plate with three pairs, occipital plate with four pairs of large annular pores; the other lattice-work loose, with small and numerous irregular polygonal pores. Apical horn and caudal feet slender and thin, curved, shorter than half the shell; two pectoral feet also small, widely divergent, more or less curved, deeply forked.

Dimensions.—Shell 0.1 long, 0.16 broad; horn and feet 0.2 to 0.25 long.

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

Subgenus 2. Tripospyrella, Haeckel.

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

5. Tripospyris triomma, Haeckel.

Shell subspherical, tuberculate, with slight sagittal stricture and circular internal ring. Basal plate with three large pores, which are sometimes (but not in every specimen) surrounded by a circle of very small pores. The other lattice-work with numerous small roundish pores. Apical horn small, oblique, about as long as the shell. Three feet very large, cylindrical, curved, widely divergent, four to five times as long as the shell. (In Ehrenberg's description the caudal foot is erroneously described as "frontal spine"; its figure exhibits the basal plate.)

Dimensions.—Shell 0.07 to 0.09 diameter; horn 0.06 long, feet 0.3 to 0.4 long.

Habitat.—Fossil in Tertiary rocks of Barbados.

6. Tripospyris conifera, n. sp. (Pl. 84, figs. 7, 7a).

Shell nearly hemispherical, papillate, with slight sagittal stricture and semicircular internal ring. Basal plate with three large pores (sometimes, as in the figured specimen, with some small accessory peripheral pores). The other lattice-work with subregular circular pores. Apical horn shorter than the three basal feet, but of similar form, like an elegant ovate dimpled cone, spinulate, with a smooth spindle-shaped pedicle, about as long as the shell.

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

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

7. Tripospyris triplecta, n. sp. (Pl. 95, fig. 2).

Shell thorax-shaped, spiny, with deep sagittal stricture and semicircular internal ring. Basal plate with three large collar pores. Facial plate with four pairs, occipital plate with three pairs of large annular pores; the other pores small, subregular, circular. Apical horn and the feet slender, three-sided pyramidal, about as long as the shell.

Dimensions.—Shell 0.1 long, 0.11 broad; horn and feet 0.1 to 0.15 broad.

Habitat.—Mediterranean, Corfu (Haeckel), surface.

Subgenus 3. Tripospyrissa, Haeckel.

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

8. Tripospyris semantrum, n. sp. (Pl. 95, fig. 3).

Shell thorax-shaped, thorny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores (two smaller ovate jugular, and two larger pentagonal cardinal pores). Facial and occipital plates also each with two pairs of large annular pores; lateral sides with smaller irregular polygonal pores. Apical horn and the three feet slender, prismatic, divergent, longer than the shell.

Dimensions.—Shell 0.07 long, 0.08 broad; horn and feet 0.11 to 0.13 long.

Habitat.—South Atlantic, Cape of Good Hope (Wilhelm Bleek), surface.

9. Tripospyris capitata, n. sp. (Pl. 84, fig. 1).

Shell subspherical, spiny, with slight sagittal stricture and ovate internal ring. Basal plate with four large collar pores. Facial plate with three pairs and occipital plate with two pairs of large roundish annular pores; lateral lattice with smaller irregular pores. Apical horn and the three feet subcylindrical, about half as long as the shell, straight, divergent, with a spherical, spinulate knob at the distal end.

Dimensions.—Shell 0.09 long, 0.1 broad; horn and feet 0.05 to 0.06 long.

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

10. Tripospyris clavata, Haeckel.

Shell subspherical, compressed, rough, with slight sagittal stricture and ovate internal primary ring. Basal plate with four large collar pores (fig. 13a, loc. cit.). The other lattice-work with irregular small roundish pores. Apical horn and the three feet short and thick, scarcely half as long as the shell, with a roundish spinulate knob at the distal end.

Dimensions.—Length of the shell 0.07 long, 0.08 broad; horn and feet 0.02 to 0.03 long.

Habitat.—Fossil in Barbados.

11. Tripospyris tessaromma, n. sp.

Shell nearly cubical, spiny, with deep sagittal stricture and subcircular ring. Basal plate with four large collar pores. Facial and occipital plates each also with two pairs of large square annular pores; lateral pores irregular polygonal. Apical horn half as long as the feet, which are three times the length of the shell, cylindrical, slightly curved.

Dimensions.—Shell 0.1 long, 0.12 broad; horn 0.15 long, feet 0.3 long.

Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.

Subgenus 4. Tripospyromma, Haeckel.

Definition.—Basal plate with six or more collar pores. Commonly two small anterior jugular pores, two large middle cardinal pores, and two small posterior cervical pores; sometimes several small accessory collar pores.

12. Tripospyris hexomma, n. sp. (Pl. 95, fig. 4).

Shell thorax-shaped, tuberculate, with deep sagittal stricture and semicircular internal primary ring. Basal plate with three pairs of pores. Facial plate with two pairs, occipital plate with four pairs of large annular pores. Lateral pores smaller, irregular, polygonal. Apical horn and caudal foot half as long as the shell and as the two pectoral feet; all four spines cylindrical, two to three times as long as the shell, slightly curved.

Dimensions.—Shell 0.1 long, 0.12 broad; horn and feet 0.2 to 0.4 long.

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

13. Tripospyris semantidium, n. sp.

Shell nut-shaped, thorny, with sharp sagittal stricture and subcircular ring. Basal plate with three pairs of large pores. Facial and occipital plates each with three pairs of large squarish pores. Lateral pores small and numerous, irregular roundish. Apical horn half as long as the shell and the three feet; all four spines straight, cylindrical, with thickened club-shaped end.

Dimensions.—Shell 0.12 long, 0.13 broad; horn 0.06 long, feet 0.15.

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

14. Tripospyris eucolpos, n. sp. (Pl. 84, fig. 4).

Shell thorax-shaped, smooth, with two vaulted bosoms, separated by a deep sagittal stricture and an internal primary ring. Basal plate constricted, with three pairs of collar pores. The other lattice-work with subregular circular pores. Apical horn and the three feet shorter than the shell, straight, divergent; their inner half thinner, cylindrical, smooth, their outer half an ovate dimpled cone.

Dimensions.—Shell 0.1 long, 0.13 broad; horn and feet 0.06 long.

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

15. Tripospyris tribrachiata, Haeckel.

Shell subspherical, smooth, with slight sagittal stricture and numerous, very small circular pores. Basal plate with numerous small pores. Apical horn and the three divergent feet very large and stout, straight, three-sided prismatic, with dentate edges, two to three times as long as the shell.

Dimensions.—Shell diameter 0.05; horn and feet 0.1 to 0.15 long.

Habitat.—Fossil in Barbados.

16. Tripospyris furcata, n. sp. (Pl. 83, fig. 11).

Shell nut-shaped, smooth, with deep sagittal stricture and broad ring. Basal plate with three pairs of small pores. Facial and occipital plates each with a pair of very large holes. Apical horn and caudal foot simple conical, two pectoral feet forked or irregularly branched.

Dimensions.—Shell 0.08 long, 0.12 broad; horn and feet 0.05 long.

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

Genus 442. Triceraspyris,^[60] Haeckel, 1881, Prodromus, p. 441.

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

The genus Triceraspyris has arisen from the preceding ancestral Tripospyris by the development of two paired frontal horns, so that the shell here bears six appendages, three superior or coryphal spines and three inferior or basal spines; two of these are odd and dorsal (the apical horn and the caudal foot), the four others are paired and ventral (the frontal horns and the pectoral feet). The numerous species of this genus may be divided into three subgenera, according to the simple or branched shape of the ascending horns and of the descending feet.

Subgenus 1. Triospyris, Haeckel, 1881, Prodromus, p. 441.

Definition.—Horns and feet simple, not branched nor forked.

1. Triceraspyris tripodiscus, n. sp.

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 three large pores. Horns and feet slender cylindrical, straight, divergent; three horns about as long as the shell, three feet twice as long.

Dimensions.—Shell 0.06 long, 0.08 broad; horn 0.05 long, feet 0.1.

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

2. Triceraspyris cortiniscus, n. sp.

Shell subspherical, smooth, with slight sagittal stricture. Pores small and numerous, subregular roundish. Basal plate with two large pores (?). Apical horn conical, short, half as long as the shell and the two lateral horns, which are curved outwards. All three feet equal, cylindrical, strongly curved and divergent, twice to three times as long as the shell.

Dimensions.—Shell 0.07 long, 0.08 broad; horn 0.04 to 0.08 long, feet 0.15 to 0.2 long.

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

3. Triceraspyris didiceros, Haeckel.

Shell nut-shaped, thorny, with superficial sagittal stricture. Pores large, irregular roundish. Basal plate with four larger pores. Apical horn and caudal foot small, conical, shorter than half the shell. The two frontal horns longer, slender conical. The two pectoral feet very large, cylindrical, nearly parallel, vertical, slightly curved, twice to three times as long as the shell.

Dimensions.—Shell 0.07 long, 0.09 broad; two sagittal spines 0.02 long, two lateral horns 0.04 long, two lateral feet 0.15 to 0.25 long.

Habitat.—Fossil in Barbados.

Subgenus 2. Triospyrium, Haeckel.

Definition.—Horns simple, not branched; feet forked or branched.

4. Triceraspyris furcata, Haeckel.

Shell nut-shaped, tuberculate, with slight sagittal stricture. Pores numerous, irregular roundish. Basal plate with four large pores. Three horns small, conical, shorter than half the shell. Three feet large, cylindrical, curved, about twice as long as the shell, forked at the distal end.

Dimensions.—Shell 0.07 long, 0.08 broad; horns 0.02 long, feet 0.1 to 0.12 long.

Habitat.—Fossil in Barbados.

5. Triceraspyris giraffa, n. sp. (Pl. 84, fig. 11).

Shell nut-shaped, mammillate, with slight sagittal stricture. Pores numerous, subregular circular. Basal plate with nine pores (three larger central and three alternate pairs of smaller peripheral, as in Pl. 87, fig. 2). Three horns equal, straight, divergent, shorter than the shell, in the basal half cylindrical, in the distal half spindle-shaped. Three feet cylindrical, twice as long as the shell, nearly parallel, vertical, at the distal end divergent, with a recurved branch near the base.

Dimensions.—Shell 0.08 long, 0.1 broad; horns 0.05 to 0.07 long, feet 0.16 long.

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

6. Triceraspyris gazella, n. sp. (Pl. 84, fig. 9).

Shell nut-shaped, tuberculate, with sharp sagittal stricture. Pores large, irregular roundish; two or three pairs of larger pores on each side of the ring. Basal plate with three large triangular pores. Three horns simple, about as long as the shell, the apical straight, the two frontal elegantly curved. Three feet somewhat longer, slender, curved, with a recurved branch near the base, repeatedly forked at the distal end.

Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.05 long, feet 0.08 long.

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

7. Triceraspyris corallorrhiza, n. sp. (Pl. 84, fig. 12).

Shell nut-shaped, spiny, with deep sagittal stricture. Pores irregular polygonal or roundish. Basal plate with two large semicircular pores. Three horns slender, simple, about half as long as the shell. Three feet of the same length, slender, divergent, irregularly branched like coral.

Dimensions.—Shell 0.06 long, 0.09 broad; horn and feet 0.03 to 0.05 long.

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

8. Triceraspyris maniculata, n. sp.

Shell subspherical, smooth, without external sagittal stricture. Pores subregular circular. Basal plate with four large pores (?). Three horns simple, straight, divergent, spindle-shaped, half as long as the shell. Caudal foot of the same form, twice as long. Two pectoral feet cylindrical, curved, twice as long as the shell, palmate, divided at the distal end into five short fingers.

Dimensions.—Shell 0.08 diameter; horns 0.04 long; lateral feet 0.12 long.

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

9. Triceraspyris longicornis, n. sp.

Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish. Basal plate with six pores (?). Apical horn short, conical, two frontal horns very large, curved, widely divergent, longer than the shell. Three feet of about the same length, irregularly branched.

Dimensions.—Shell 0.08 long, 0.12 broad; lateral horns and feet 0.15 to 0.2 long.

Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.

Subgenus 3. Triospyridium, Haeckel.

Definition.—Horns and feet forked or branched.

10. Triceraspyris damaecornis, n. sp.

Shell nut-shaped, smooth, compressed, with broad sagittal ring. Pores irregular roundish; one pair of very large pores on each side of the ring. Basal plate with four large collar pores. Three horns and three feet short, divergent, slightly curved, about half as long as the shell, irregularly branched. (In general form very similar to Elaphospyris damaecornis, Pl. 84, fig. 10, with which I formerly confounded it.)

Dimensions.—Shell 0.08 long, 0.12 broad; horns and feet 0.04 long.

Habitat.—South Pacific, Station 295, depth 1500 fathoms.

11. Triceraspyris arborescens, n. sp.

Shell subspherical, with deep sagittal stricture. Pores irregular roundish; three pairs of larger pores on both sides of the ring. Basal plate with two large collar pores. Three horns about half as long as the shell, with few irregular terminal branches. (Beginning of a cupola.) Three feet strong, cylindrical, twice as long as the shell, richly branched, arborescent.

Dimensions.—Shell 0.09 long, 0.1 broad; horns 0.05 long, feet 0.2 long.

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

Genus 443. Tristylospyris,^[61] Haeckel, 1881, Prodromus, p. 441.

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

The genus Tristylospyris exhibits in general the same structure as the typical genus Tripospyris, its ancestral form. It differs from the latter in the absence of the apical horn, which is completely reduced, and may therefore be regarded as the simplest prototype of all tripodal Cyrtellaria without a horn.

Subgenus 1. Tristylospyrula, Haeckel.

Definition.—Feet simple, not branched nor forked.

1. Tristylospyris palmipes, n. sp. (Pl. 84, fig. 14).

Shell companulate, smooth, with slight sagittal stricture. Pores irregular roundish, three pairs of larger annular pores on each side of the broad ring. Basal plate with four large collar pores. Feet half as long as the shell, slightly divergent, straight, prismatic, with a broad, hand-like, radially striped plate at the distal end.

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

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

2. Tristylospyris scaphipes, n. sp. (Pl. 84, fig. 13).

Shell nut-shaped, smooth, with sharp sagittal stricture. Pores very small and numerous, circular; two pairs of larger pores on both sides of the ring. Basal plate with four large pores (?). Feet about half as long as the shell, angular, shovel-shaped, straight, parallel, vertical.

Dimensions.—Shell 0.06 long, 0.08 broad; feet 0.04 long.

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

3. Tristylospyris clavipes, n. sp. (Pl. 84, fig. 15).

Shell nut-shaped, rough, with deep sagittal stricture. Pores small, subregular circular. Basal plate with three large pores. Feet about as long as the shell, slender, straight, divergent, with a spinulate knob at the thickened distal end.

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

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

4. Tristylospyris triceros, Haeckel.