88 Trans. Acad. Sci. of St. Louis. 



Suborder Basommatophora. 



Superfamily Akteophila. 



Family Auriculidae. 

 Genus Carychium Miiller. 



101. Carychium exigudm Say. 



Station 5. Rochester (Walton) ; Cayuga (Banks). 



Superfamily Hygrophila. 



Family Limnaeidae. 



Subfamily Limnaeinae. 



Genus Limnaea Lamarck. 



102. Limnaea stagnalis Linne. 



Stations 3 and 15. Brighton (Walton). Very abundant 

 and of large size ; found crawling over sticks and other debris 

 in a few inches of water at station 3. There is considerable 

 variation in the form of the aperture, some being almost 

 round while others are long and narrow. The spires in these 

 specimens, however, are of about the same length. Some 

 individuals have fine spiral lines encircling the whorls. 



Section Radix Mont. 

 *103. Limnaea columella Say. 



Section Limnophysa Fitz. 

 *104. Limnaea reflexa Say. 



105. Limnaea palustris Miiller. 



Stations 3, 5, 6, 9, 10, 11 and 17. Erie Canal (Walton). 

 Common and variable. The L. elodes Say of Walton's list is 

 a synonym. 



106. Limnaea catascopium Say. 



Stations 3, 4, 8 and 15. Erie Canal (Walton). Very com- 

 mon and exceedingly variable. The typical catascopium is a 



