94 



** Operculum granular. 



N. ornata (tig. 4). The younger shells have the inner lip more 

 granular, and the adult more ridged. 



4. Operculum uniform, granular, without any raised or distinct 

 submarginal band. Natere. 



N. exuvia. 

 N. Malaccensis. 

 N. albicilla (fig. 6). 

 iV. Senegalensis. 



Inner lip granulated. 



1. Nerita polita. 

 4. N. ornata. 



N. variabilis. 

 N. Chameleon. 

 N. versicolor. 

 N. tessellata. 



2. N. lineolata. 

 5. N. Peloronta. 



** Inner lip ridged. 



3. N. plicata. 

 6. N. albicilla. 



*** Inner lip smooth. 



N. signata. The granules large, in lines. 



N. atra. 



N. inconspicua. 



The Puperita pupa, from the West Indian Seas, has an oper- 

 culum of a single coat, with a polished surface like Neritina. This 

 genus, in the ' Guide to the Mollusca in the British Museum,' 

 is hy mistake put in the same section as Nerita, instead of that of 

 Neritina (see p. 137). 



