Page:Scientific results HMS Challenger vol 18 part 2.djvu/158

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Definition.—Feet forked or branched.

5. Tristylospyris furcata, n. sp.

Shell subspherical, rough, with slight sagittal stricture. Pores subregular circular. Basal plate with three large collar pores. Feet cylindrical, three to four times as long as the shell, strongly curved and divergent, at the distal end forked, with two short (sometimes ramified) branches.

Dimensions.—Cephalis 0.08 long, 0.09 broad; feet 0.2 to 0.3 long.

Habitat.—South Atlantic (off Patagonia), Station 318, surface.

6. Tristylospyris ramosa, n. sp. (Pl. 52, fig. 23).

Shell subspherical, tuberculate, with a prominent sagittal ring. Pores irregular roundish. Basal plate with three large pores. Feet large, straight, widely divergent, about twice as long as the shell, prismatic, irregularly branched. (Compare the following species.)

Dimensions.—Shell 0.08 in diameter; feet 0.15 long.

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

7. Tristylospyris tripodiscium, n. sp. (Pl. 52, fig. 22).

Shell subovate, tuberculate, very similar to the preceding species. It differs from this in the very different size of the irregular pores and the greater breadth of the pedal branches. The basal plate in a complete specimen (observed afterwards from the base) exhibited four large collar pores of the usual form, whilst in the similar preceding species it had three pores. In the similar Tripodiscium sphærocephalum (Pl. 52, fig. 21) the basal mouth is quite simple and open.

Dimensions.—Shell 0.09 long, 0.1 broad; feet 0.12 long.

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

Definition.— with three basal feet and two large apical openings or coryphal holes, one on each side of the ring-apex. No true horns.

The genus Cephalospyris comprises some few Tripospyrida of very peculiar shape, differing from all other Zygospyrida in the possession of two large apical holes or coryphal apertures, lying on each side of a latticed sagittal septum, which is formed by the upper part of the sagittal ring. The sagittal stricture is deep, with a complete