SMITH : TWO SPECIES OF MADAGASCAN HELICES. 337 



S. partumeium Say. 



S. Jayanum Prime. Originally described from Lake 

 Superior. In the summer of 1875 I obtained a single specimen 

 at Houghton Lake, Roscommon county. Its actual occurrence 

 in the state is thus made certain. 



S. transversum Say. 



S. secure Prime. 



S. truncatum L. 



Pisidium virginicum Bourg. 



P. Adam si Prime. Prime, Currier. 



P. aequilaterale Prime. 



P. compressum Prime. 



P. variabile Prime. 



P. abditum Hald. 



P. ,, var. abyssorum Stimpson MSS. Smith. 



A " very small translucent form " from the great lakes. Originally 

 obtained in the deep waters of Lake Michigan. According to 

 Smith it has been dredged from a depth of 159 fathoms in Lake 

 Superior. 



DESCRIPTIONS TO TWO SPECIES OF HELICID^ 



FROM MADAGASCAR, 



By EDGAR A. SMITH, F.Z.S., 



Zoological Department British Museum. 



The list of species of Madagascar land shells is, I conclude 



by no means yet complete, for almost every collection of any size 



which reaches this country appears to present a few novelties. 



The two forms about to be described were collected by two 



gentlemen, the Rev. W. D. CoAvan and Mr. C. Shaw, engaged in 



missionary labour, out of respect for whom I have much pleasure 



