Page:Scientific results HMS Challenger vol 18 part 2.djvu/265

Rh the shell. Three feet slender cylindrical, widely divergent, curved, nearly twice as long as the shell.

Dimensions.—Shell 0.08 long, 0.14 broad; horn 0.05 long, feet 0.15 long.

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

3. Tripilidium lychnocanium, n. sp.

Shell hemispherical, thorny, one and a half times as broad as long. Pores regular, circular, hexagonally framed, as broad as the bars. Mouth slightly constricted. Apical horn stout and short, three-sided pyramidal. Three feet cylindrical, straight, divergent, twice to three times as long as the shell. (Similar to Lychnocanium favosum, Pl. 61, fig. 6, perhaps derived from it by reduction of the cephalis.)

Dimensions.—Shell 0.08 long, 0.12 broad; horn 0.02 long, feet 0.2 long.

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

4. Tripilidium ovatum, n. sp.

Shell ovate, smooth, one and one half times as long as broad. Pores regular, circular, as broad as the bars. Mouth constricted, half as broad as the shell. Horn short, conical. Three feet conical, curved, convergent, scarcely one-third as long as the shell.

Dimensions.—Shell 0.15 long, 0.11 broad; horn 0.02 long, feet 0.04 long.

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

5. Tripilidium clavatum, n. sp.

Shell nearly spherical, tuberculate, a little broader than long. Pores regular, circular, as broad as the bars. Mouth constricted, half as broad as the shell. Apical feet and the three divergent feet of equal size and similar form, about as long as the shell, straight, in the basal half smooth, cylindrical, in the distal half club-shaped, dimpled. (Very similar to Tripospyris conifera and Tripospyris eucolpos, Pl. 84, figs. 7 and 4; but the spherical shell exhibits no trace of sagittal ring or constriction, and the simple shell-cavity has a wide open mouth, and is not closed by a basal plate.)

Dimensions.—Shell 0.1 diameter, horn and feet 0.08 to 0.09 long.

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

6. Tripilidium costatum, n. sp. (Pl. 98, figs. 8, 8a, 8b).

Shell ovate, spinulate and costate, nearly twice as broad as long. Surface with fifteen to twenty prominent longitudinal ribs, which are convergent towards each pole and elegantly denticulate. The deep furrows between them are divided by delicate, parallel, transverse ribs into numerous short and broad dimples (thirty to forty in each furrow); each dimple contains a small pore, like a transverse