Pneumonobranchiate Mollusca. 



331 



Arioxid^. 



The Nanina Albinensis, N. Otaheitana, and N. Panayensis all 

 have very numerous nearly uniform teeth, close together on a 

 very broad lingual band. 



Parmacella ( Olivieri) . The teeth numerous in very close cross 

 lines, with a compressed elevated central ridge with a flat edge 

 ending in two teeth. 



Testacellid^. 



Fig. 1. Testacellus. 



Lingual membrane broad ; teeth numerous in diverging cross 

 series, those of the first six or seven lines yellow, the first 

 darkest, the rest transparent, without any in the central series ; 

 the teeth pinshaped, slightly curved, with a roundish head and 

 an acute tip, only attached to the thin lingual membrane by a 

 small central process (see fig. 1). 



Helicid^. 



Fig. 2. Achat ina fulica. 



. I " I If I 



In this and the following figures, c represents the central, I the lateral, 



and u the exterior lateral teeth. 



The teeth of all the exotic species I have examined are like 

 those described in the European kinds. I figure the teeth of 

 Achatina fulica (fig. 2), as the teeth of that genus have not before 

 been described ; they are numerous in each cross series, those of 

 the two central series are small ; they are all small, four-sided, 

 rather broader than long, with a blunt rather large central tip. 



The teeth of Partula {faba) are like those of Bulimus ; they 

 are placed on a broad pale yellowish lingual membrane in 

 numerous straight transverse lines on each side of the central 

 line, and are equal and uniform. 



VEROXICELLIDiB. 



The teeth of Veronicella are very like those of Bulimus. The 



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