Page:Scientific results HMS Challenger vol 18 part 2.djvu/156

1032 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.

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.

Definition.— 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