Species Dubiæ.
3. [PLATYLEPAS] --------?
Hab.—Imbedded in the skin of a sea-snake, taken off Borneo.
I am indebted to Dr. Gray for a single specimen of this supposed species, but as it is very young and imperfect, wanting the opercular valves and cirri, I do not choose to name it. The shell presents all the usual characters of the genus; the rostrum, I may remark, being pushed to the left side. The parietes are permeated by pores of considerable size, which shows that the species is distinct from [P. decorata]. On the inner basal surfaces of the walls, there are two or three very distinct ridges on each side of the midrib; and this fact, together with the size of the parietal pores, makes me suspect that it is not an immature specimen of [P. bissexlobata].
10. Genus—TUBICINELLA. Pl. [17], fig. [3 a]-[3 c].
TUBICINELLA. Lamarck. Annales du Museum, tom. 1 (1802), Tab. 30, fig. 1.
CORONULA. De Blainville. Dict. des Sciences Naturelles, (1824).
Compartments six, of equal sizes; shell sub-cylindrical, wider at the top than at the basis, belted by several large transverse ridges.
Hab.—Southern Pacific Ocean, Western South America, New South Wales, Cape of Good Hope; imbedded in whales, and often associated with [Coronula balænaris].