NuMBKR 51 April 16, 1918 



OCCASIONAL PAPERS OF THE MUSEUM OF 

 ZOOLOGY 



UNIVERSITY OF MICHIGAN 



Ann Ardor, Michigan Published by the University 



PinUROBEMA CLAVA (LA^L) AND PLAN ORB IS 



DILATATUS BUCHANENSIS (LEA) 



IN MICHIGAN 



By Mina L. Winslow 



During the summer of 1917 the Museum of Zoology sent 

 expeditions to Hillsdale, Branch, and Berrien Counties, in the 

 extreme southern part of ^Michigan. A study of the mollusks 

 of this region resulted in additional records for each county, 

 among them two species new to the state. Of these Plcnro- 

 bcina clava (Lam.) represents a genus not before recorded for 

 Michigan, but whose presence was expected since its range as 

 given by Sterki^ and Simpson- includes the Maumee Basin. 

 Clark and Wilson^ list this species from the Upper Maumee 

 and the St. Joseph. 



The only specimen procured was taken between Woodbridge 

 and Amboy Townships, Hillsdale County, in a small branch of 

 the St. Joseph of the Maumee. The stream was at this point 



1 Proc. Ohio St. Acad. Sci., Vol. IV, 1907, Pt. 8, p. 392. 

 ^Descriptive Cat. of the Naiades, 1914, p. 736. 

 ^ Bur. Fish., Doc. 757, 1912, p. 43. 



