Occasional Papers of the Museum of Zoology 9 



mens were taken from dead reeds and debris at the edge of 

 Sweetwater Lake. The animal is very large and of a pale 

 buff color. 



Siicciiica haydcni minor W. G. B. Court Lake. Fort Totten 

 Lake. Lac aux Morts, Upsilon Lake. Lake Metagoshe. Carpen- 

 ter Lake, Bottineau. This may be only an ecological form of 

 haydcni, according to Pilsbry. It is variable in outline and 

 in the angle of the aperture. 



Gastrocopta armifcra similis Sterki. IMauvaise Coulee, 'Sle- 

 dora, Buford. \\'illiston. 



Gastrocopta contracta (Say). \\'ood Lake. A single spec- 

 imen, from debris at the edge. 



Gastrocopta holzingrri (SterkiL Devils Lake, Mauvaise 

 Coulee, ?*Iedora, Buford, Williston. 



? J'crtigo coloradcnsc Ckll. "Probably a form of colorad- 

 cnsc Ckll., the same as I have from western Alontana and 

 nearly the same from \\ innipeg" (Sterki. ) 



J'ertigo gouldii (Binney). Devils Lake. A few examples 

 only. 



J'crtigo irntricosa clatior Sterki. L'psilon Lake. 



Vertigo ovata Say. Devils Lake, Court Lake, Lac aux 

 Alorts, Upsilon Lake, Gravel Lake. Those taken at Court 

 Lake were found on a wet log half in the water. 



\ ertigo sp. Buford, Williston. 



Pnpilla mnscorum (L.). Devils Lake, Court Lake, ^Nlau- 

 vaise Coulee, Stump Lake, Medora, Williston. Extremely 

 abundant wherever taken. Dr. Sterki notes that it is this spe- 

 cies "with slight variation." 



Gochicopa lubrica (Miiller). Devils Lake. Court Lake, 

 Mauvaise Coulee, Gravel Lake, Bottineau. 



