66 Zoological Society : — 



2. Operculum polished, with a broad, slightly raised, granulated, 

 submarginal band. Ritena. 



N. plicata (fig. 3). 



The specimens vary slightly in the distinctness, and especially in 

 the breadth, of the tubercular submarginal band. 



3. Operculum with a broad, raised, convex, smooth, submarginal 



band. Tenare. 



* Operculum smooth. 

 - N. Peloronta (fig. 5). 



** Operculum granular. 



N. ornata (fig. 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. 



* Inner lip granulated. 

 N. exuvia. 

 N. Malaccensis . 

 N. albicilla (fig. 6). 

 N. Senegalensis. 



ttt 



ft* 



1. Nerita polita. 2. N. lineolata. 3. N. plicata. 



4. N. ornata. 5. N. Peloronta. 6. N. albicilla. 



** Inner lip ridged. 

 N. variabilis. 

 N. Chamceleon. 

 N. versicolor. 

 N. tessellata. 



*** 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- 



