2 University of Micliigan 



The writer is indebted for generous assistance in the de- 

 termination of species, exclusive of the Sphreriidae, to Dr. 

 Bryant Walker, of Detroit, and in the determination of the 

 Sphaeriidje to Dr. Victor Sterki, of New Philadelphia, Ohio. 



By way of a systematic summary it may be noted that the 

 species fall into the following groups : 



Terrestrial, 19 species and Flnviatilc, 46 species and 



varieties : varieties^ : 



Family. Genus. Species. Family. Genus. Species. 



Helicidge i 2 Lymnaeida; 3 6 



Zonitidse 3 6 Physidse r 8 



Limacidse 2 2 Plknorbidse i 10 



Philomycidse . . . i i Ancylidse i i 



Endodontidse ... 2 4 Viviparidse i 2 



Succineidse i 2 Amnicolidge i i 



Pupillidae i i Unionidae .4 6 



Cochlicopidie . . . i i Sph?eriidse 3 12 



]2 19 15 46 



List of Species. - 



I. Polygyra albolabris (Say). — Schoolcraft: Several 

 specimens were found on rotten wood and leaves along the 

 Alanistique River and in the hardwood forest. They are 

 rather frail shells, with the exception of No. 33 which is quite 

 solid and of a pale yellow color. Alger: From the hardwood 

 forest. Of the eleven specimens three are immature. Chip- 

 pewa : Found in the road after a rain. Others from hardwood 

 forest and spruce-cedar swamp near Vermilion. Eggs and 

 young shells were collected near Vermilion. The smallest 

 measure alt. 2, diam. 3.25 mm. ; the largest, thirty-two days old. 



^ Two species not represented in these collections (Physa heterostropha Say 

 and Sphaerium simile Say) have been listed from Chippewa County (Hankinson, 

 pp. 118, 132, 133. 134. 135)- 



- In the list of species the localities referred to are counties unless otherwise 

 stated. 



