Baker—Molluscan Fauna of Tomahawk Lake, Wisconsin . 217 
Station XXI. 
Swampy tracts along margin of river, separated from the lat¬ 
ter by a high ridge. These depressions vary in extent from a 
few feet to several hundred feet in diameter, and also vary in 
depth. The vegetation consists of swamp grass, Iris and Typha . 
MOLLUSCA COLLECTED. 
Sphcerium occidentale. 
Musculium partumeium. 
Pisidium subrotundum. 
Physa gyrina. 
Aplexa hypnorum. 
Planorbis hirsutus. 
Segmentina armigera. 
Vitrea hammonis. 
It is noteworthy that the mollusk fauna of this station is sim¬ 
ilar to that noted in some of the summer dry ponds of the 
Skokie Marsh area in Illinois. 
Station XXII. 
Gilmore Creek, a small tributary of the Wisconsin River, 
emptying into the latter four miles northeast of Sanders’ Resort. 
The water is shallow, from a few inches to two or three feet in 
depth, and the bottom consists of clean, firm sand. The current 
is swift and the water clear. Xaiads are abundant buried in 
the sand in company with Campeloma. Muskrat heaps are a 
common sight, showing that this animal resorts frequently to 
this region for its food supply. The preponderance of pelecy- 
pods at this station is notable. 
