1872.] MR. A. GARRETT ON NEW SHELLS. S79 



vertical, fringed with the ends of the keels ; umbilicus deep, in 

 width equal to one fifth the greatest diameter of the shell ; columella 

 nearly vertical, slightly arched. 



Length 4| mill., diam. 3 mill. 



Hub. Paumotu Islands. 



The keels are more prominent than in S. blainvilleana, the base 

 more depressed ; otherwise it closely resembles that species. The 

 wide space between the basal and three upper keels is concave; and the 

 remote rugosities on the keels give the shell a polyangular appearance. 



Separatista stellaris. 



Shell small, turbinate, subrhomboidal, thin, horn-colour under a 

 fibrous muddy brown epidermis, which is fringed with distant coarse 

 hairs on the periphery ; spire conical, about half the length of the 

 shell ; whorls 5 (two of which are embryonal), angulated, the last 

 large, subdiscoidal, with three small transverse keels on the peri- 

 phery, the upper two traversing the lower half of the whorls of the 

 spire, and two keels on the umbilical region ; aperture large, semi- 

 circular, wider than long, slightly effuse beneath ; outer lip thin, 

 continuous, strongly arched, the epidermis slightly overlapping the 

 margin ; columella subvertical and slightly expanded ; umbilicus 

 deep, in width equal to one fifth the greatest diameter of the shell. 



Length 5 mill., diam. \\ mill. 



Hab. Samoa and Viti Islands. 



In this species the body is more depressed, and the keels smaller 

 than in the preceding. Several examples were found attached to a 

 sponge. 



8. Descriptions of two new Species of Ccecum from the Viti 

 Islands. By Andrew Garrett, of Tahiti. 

 [Eeceived August 12, 1872.] 



CjECTJM vitiense. 



Shell cylindrical, slightly arched, contracted towards the aperture, 

 thin, subpellucid, glossy, light tawny brown, and under the lens 

 closely and finely striated transversely ; the aperture, owing to the 

 contraction of that part of the shell, is nearly as small as the 

 decollated apex, and is very oblique. 



Length 2| mill. 



A single but perfect example was found at Kioa Island. 



CAECUM COSTULATUM. 



Shell cylindrical, slightly arcuated, thin, pellucid, white ; surface 

 glossy, with obsolete lines of growth, and the anterior end with several 

 closely set annular ridges ; aperture very oblique, not contracted. 



Length 3 mill. 



Several examples were found on sandy beaches at Kioa Island. 



The above two species are probably the only ones described from 

 the South-Sea Islands. 



