316 SYRNOLOrSlS. 



lamellae, the second a single one. In consequence of this divi- 

 sion, the above species is placed among those having two 

 lamellae, and the figure of it given by Mr. Crosse (fig. 56) is 

 made a new species under the name of S. Grandidieri, because 

 of having only one lamella. I do not believe the distinction 

 will hold good, as these plicae are either developed or entirely 

 absent in the same species in Pyramidellidne. 



Unfigured Species. 



S. HAMYANA, S. ANCEYANA, S. GIRAUDT, S. MINUTA, all of 

 Bourguignat. Lake Tanganyika. 



