W. R. R. A peculiar form, showing some ressem- 

 blance with Gundlachia. 



80. Ancylus diaphanus Hald. Common, especially in 



the Tuscarawas river. Variable, as there are spec- 

 imens vvith a low and blunt apex. 



81. ANCYiiUS TARDUS Say. Not very common, in the 



river and Stillwater creek; variable. 



82. Ancylus RivuiiARis Say. Very common, especially 



in the river, 

 a. var.? larger, and different otherwise; scarce, in pools. 



83. Ancylus ? Not scarce, in the river; a very 



peculiar, small species, only 2 mill, long, narrow, 

 with the sides parallel, high. 



a. ? var. of the preceding ? Somewhat larger, outline 



elliptic. 



The North American Ancyli need a careful revis- 

 ion, with anatomic examination. — Not to Prof. B. 

 Shimek, as said in the introduction, but to Mr. 

 Chas. T. Simpson, of the U. S. National Museum, I 

 am indebted for looking over some of our Ancyli. 



84. BuLiNUS HYPNORUM Lin. Not common, variable in 



size and shape. 



85. Physa heterostropha Say. Very common and 



variable. An albin specimen has been found. 

 ■A. var. GYRINA Say. Common; also intermediate spec- 

 imens. 



b. var. (?) . Very small (6—7 mill, high), near Den- 



nison. 



86. Physa . Tuscarawas river and Ohio canal. It 



has been taken for Ph. heterostropha; but there are 

 decided anatomic differences; also the shell is dif- 

 ferent. 



87. Melantho INTEGRA Say.' Common in the Tusca- 



rawas river and Ohio canal; inverse specimens not 

 rare,, and the soft parts in them are also inverse. 



88. Somatogyrus isogonus Say. Rare, in the same 



places. 



89. Amnicola decisa Hald. Rare. 



90. A:\ixicoLA orbiculata Lea. Common, especially 



in the Ohio canal and mill race on the river. 



