128 THE NAUTILUS. 
are similar to the Canadian examples, which he refers to that spe- 
cies. 
Carychium exiguum Say. 
Limniea stagnalis L. 
Limnrea catascopium Say. 
Two forms of this species are represented in the collection. One 
from the Saginaw River is of the usual form, but of unusual size, 
one example being nearly one and one-fourth inches in length. 
The other form from Saginaw Bay is characterized by its greatly 
inflated body whorl and very short, rapidly acuminating spire. A 
single specimen from Lake Huron represents the form usually found 
in the Great Lakes. 
Limnea reflexa Say. Bayou, East Saginaw and Saginaw Bay. 
The latter somewhat smaller and more slender than the former. 
Limnzea reflexa sealaris. Intermediate between the type and the 
variety. 
Limnzea palustris Mull. Larger than the average in size. The 
striped variety corresponding to form of L. refleca known as zebra 
Tryon, is also represented. 
Limnea cubensis Pfr. 
Physa ancillaria Say. Saginaw Bay. 
Physa sayil Tapp. 
Physa gyrina hildrethiana Lea. 
Aplexa hypnorum L, 
Planorbis trivolvis Say. 
Planorbis bicarinatus Say. 
Planorbis campanulatus Say. 
Planorbis albus Mull. 
Planorbis exacutus Say. 
Planorbis paryus Say. Among anumber of the usual form of this 
species occurs one of the curiously distorted examples, in which the 
whorls almost from the apex are entirely detached from each other 
and coiled obliquely like a ram’s horn. 
Segmentina armigera Say. 
Ancylus fuseus Ad. Saginaw River. 
Ancylus parallelus Hald. Saginaw River. Much narrower and 
with the sides more flattened and hence more nearly parallel than 
in specimens from other localities. 
Lyogyrus pupoidea Gld. Heretofore this species has been cited 
only from the western part of the State. 
