214 Wisconsin Academy of Sciences, Arts, and Letters. 
MOLLUSCA COLLECTED. 
Lymncea lanceata. 
Planorbis bicarinatus unicarinatus. 
Planorbis trivolvis. 
Segmentina armigera. 
Physa ancillaria warreniana. 
Musculium securis. 
Station XVI. 
Bass Lake one mile north of Sanders’ Resort. A small lake, 
with soft, mucky bottom, occupying a deep Hollow or kettle hole. 
A stream flows from the lake into the artificial pond at Sta¬ 
tion XV. The only mollusk observed was Physa ancillaria 
warreniania. 
Station XVII. 
Small pools in swales (kettle holes) west of Sanders’ Resort. 
The whole country is rolling, and every depression contains a 
small pond or swampy pool. The ground is very marshy, the 
vegetation consisting of Iris and Typha, besides a kind of swamp 
grass. The plants in this vicinity were literally swarming with 
aphids. Pisidium was the principal mollusk observed, though 
a few Ancylus and Planorbis were secured from the surface of 
sticks. 
MOLLUSCA COLLECTED. 
Ancylus parallelus. 
Planorbis parvus. 
Pisidium abditum. 
Pisidium roperi. 
Musculium rosaceum . 
