2 University of Michigan 



state that the list can be considered, only a preliminary one. 

 Exploration of the extreme northeastern corner of the state 

 and of the Red River is especially desirable and would un- 

 doubtedly add many species to the present list. 



During the summer of 1919 an opportunity was offered to 

 collect mollusks in North Dakota through the generous co- 

 operation of Dr. R. T. Young. Director of the State Biological 

 Station at Devils Lake, X. I)., with the INFuseum of Zoology. 

 The work was undertaken as part of a survey of the fauna 

 of the state, begun by Miss Crystal Thompson for the State 

 of North Dakota. A careful study of the immediate vicinity 

 of Devils Lake was i)ossible, together with a reconnaissance 

 of nearby localities. In the Turtle Mountains five days were 

 devoted to collecting and a general survey of a topography 

 dift'ering widely from that of the Devils I^ake region. Every 

 facility was offered for work and the care of material at the 

 Station, and trips into the surrounding country were com- 

 paratively easy. 



Further collecting in the western part of the state in 1920 

 by Miss Thompson and N. A. Wood, of the Museum of Zo- 

 ology, resulted in the addition of several species and locality 

 records to the 1919 list. Collections of drift rich in small 

 land shells were taken from the banks of the Missouri and the 

 Little Missouri at various points. 



Without the help of Mr. .Alfred Eastgate, Deputy Game 

 W arden, the work in the Turtle ?\lountains could not have in- 

 cluded so much territory. With his assistance we were able 

 to collect in widely separated localities. Mr. Eastgate also 

 contributed clams and Sphseriidae from the Sheyenne River. 



A large proportion of the 1919 collection has been sub- 

 mitted to specialists for identification, and most of the identi- 

 fications by the writer have been verified by them. I am under, 

 obligations to the following persons for examining and nam- 



