36 



85. Ancylus rivularis Say. Very common especially 



in the river. 

 A var.(?) is larger and somewhat different in 

 shape; scarce in pools. 



86. Ancvlus—"^ Not scarce, in the river. Only two 



millimeters long when mature, narrow, with 

 the sides paralled. rather high. Has been 

 filed, for years, under the M. S. name A. 

 pumilus, and is evidently a distinct n. sp. 

 The North American Ancyli need a careful 

 revision, with onatomic examination. 



87. Apkxa hypnorum Lin. Scarce. Found near 



Midvale. 



88. Physa heterostropha Say. Common and vari- 



able. An albin (perfectly colorless) specimen 

 has been found. Var. gyrina Say. Common. 



89. Phvsa — ^ Very small, seems distinct. Near 



Dennison. 



90. Physa (? ancillaria) Tuscarawas river. Sugar 



Creek, Ohio Canal, etc. It has been identified 

 as heterostropha, but is decidedly distinct as 

 to shell and anatomy. 



91. Physa — ? Also doubtless a distinct species. 



The shell is like that of Aplexa hypnorum, for 

 which it has been mistaken, but much 

 smaller; the pallial fringes and the radul are 

 those of a Physa. Has been noticed for years 

 and was also received from other States. 

 (Ms. name: Ph. aplectoides.) 



92. Campeloma Integra Say. Common. Inverse 



specimens are numerous. Some examples 

 identified as C. rubra are not distinct. 



93. Somatogyrus isogonus Say. River and Ohio 



Canal, rather scarce. 



94. Amnicola decisa Hald. Rare. 



95. Amnicola orhiculata Lea. Common in the river, 



race and Ohio Canal. 



96. Amnicola parva Lea. Ohio Canal, notcommon. 



