Page:Scientific results HMS Challenger vol 18 part 2.djvu/245

Rh 2. Botryocyrtis theocampe, n. sp. (Pl. 96, fig. 19).

Cephalis quadrilobate; the odd frontal and the two paired buccal lobes hemispherical, about half as large as the helmet-shaped occipital lobe. Thorax cylindrical, of equal length and breadth, one and a half times as broad as the cephalis and as the cylindrical abdomen. Pores rather large, irregular, roundish.

Dimensions.—Length of the shell 0.12, breadth 0.06.

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

3. Botryocyrtis cerebellum, n. sp. (Pl. 96, fig. 18).

Cephalis quinquelobate; the odd frontal and the two paired buccal lobes ovate, about half as large as the two helmet-shaped paired occipital lobes (?). Thorax campanulate, twice as broad and long as the cephalis and as the truncate cylindrical abdomen.

Dimensions.—Length of the shell 0.12, breadth 0.08.

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

4. Botryocyrtis quinaria, Ehrenberg.

Botryocyrtis quinaria, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. x. fig. 16.

Cephalis quinquelobate; the odd occipital lobe ovate, twice as large as each of the other four subspherical lobes, the two anterior (or frontal) of which are somewhat smaller than the two posterior (or buccal). Thorax campanulate, somewhat larger than the truncate abdomen. Pores rather large, irregular.

Dimensions.—Length of the shell 0.09, breadth 0.05.

Habitat.—Indian Ocean (Zanzibar and Madagascar), surface.

Definition.— with tubes on the cephalis, and with the mouth of the abdomen open.

The genus Pylobotrys differs from the closely allied Acrobotrys, its ancestral form, in the development of an abdomen or a third shell-joint, the basal mouth of which remains open.

1. Pylobotrys putealis, n. sp. (Pl. 96, fig. 21).

Cephalis multilobate, with a single curved and descending tube on the base of its anterior part (sternal tube). Occipital half of the cephalis divided into three large odd lobes (the largest