Dimensions.—Length of the shell 0.08, breadth 0.06.
Habitat.—Western Tropical Pacific, Station 225, depth 4575 fathoms.
6. Lithobotrys mascula, n. sp. (Pl. [96], fig. 16).
Cephalis sexlobate, with two divergent cylindrical tubes, an ascending apical tube in the apex of the helmet-shaped occipital lobe and a descending sternal tube on the base, between the two kidney-shaped frontal lobes. The latter are half as large as the odd occipital lobe and of about the same size as the two inflated lateral buccal lobes, which are separated by a small odd nasal lobe.
Dimensions.—Length of the shell 0.13, breadth 0.08.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
7. Lithobotrys orchidea, n. sp. (Pl. [96], fig. 17).
Cephalis sexlobate, similar to the preceding species, but with five divergent and curved cylindrical tubes, which correspond to the five spines of Stephanium; an apical tube on the apex of the occipital lobe, a caudal tube on its base, a sternal tube between the two frontal lobes, and two paired pectoral tubes between the latter and the lateral buccal lobes. Pores small and scarce.
Dimensions.—Length of the shell 0.12, breadth 0.06.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.