UNIVERSITY OP MICHIGAN 



MUSEUM OF ZOOLOGY 

 Miscellaneous Publications No. 6 



A Synopsis of the Classification of the Fresh- 

 Water MoUusca of North America, 

 North of Mexico, 



AND 



A Catalogue of the More Recently 

 Described Species, With Notes 



BY 



BRYANT WALKER 



ANN ARBOR, MICHIGAN 



PUBLISHED BY THE UNIVERSITY 

 Decicmber 30, 1918 



