428 



TROCIIIiYiE. 



Species of Photinula. 



cserulesceus, King. 

 expansa, Soii\ 

 fusca, A. Adams. 

 lineata, Gray. 

 nigra, A, Adams. 



Sanclwichiaiia, /i. Adams. 

 sigaretiua, Sow. 

 tseniata, Wood. 

 violacea, Kinrf. 



Genus ClILOROSTOMA, Swainson. 



Shell conoidal, usually deeply umbilicated, or with the 

 umbilical region covered by a callus ; whorls smooth or 

 longitudinally corrugated, the last generally keeled at the 

 periphery ; aperture oblique ; inner lip with an acute tu- 

 bercle at the fore part, continuous with a spiral ridge which 

 encircles the umbilicus ; outer lip angular at the base, usu- 

 ally with one or two tubercles. 



Ua:. C. argyrostoraa, Chemnitz, pi. 49, fig. 1. Oper- 

 culum, C. atrum. Lesson, fig. 1, a. 



The peculiar feature in the shell of Ghlorostoma is the 

 spiral ridge which encircles the umbilical region and ends 

 at the fore part of the inner, lip usually in a short tooth or 

 tubercle ; the shells are remarkable for their black or 

 dingy colour. 



Species of Chlurostoma. 



argyrostoma, Chem. 

 atrum, Lesson. 

 bicanaliculatum, Dkr. 

 bicarinatum, Pot. and Mich. 

 brunueum, Phil. 

 castaueum, A. Adams. 

 leucostigma, A. Adams. 



luctuosum, D'Orh. 

 lugubre, Gviel. 

 maculosum, A. Adams. 

 marginatum, Nutt. 

 mitra, Anton. 

 moestura, Jonas. 

 nigerrimum, Gmel. 



