1896] NATURAL SCIENCES OF PHILADELPHIA, 187 



by the industry of the muskrats inhabiting every large stream 

 in my course and whose diet seemed to consist very largely of these 

 mollusks, which they would collect and deposit on logs by the mar- 

 gin of the water. When the mussel dies, the valves of the shells re- 

 lax and the muskrat devours the contents, dropping the shells into 

 the water. In some places I found many bushels of these shells 

 representing ten or fifteen species and three genera in one dumping 

 place, and was able to get a piuch better represention of this part of 

 the mollusk fauna in an hour than would have been possible in a 

 day's dredging or wading. In a fish-dam on the Holston River, 

 near its junction with the French Broad, I found these shells wedged 

 among the stones by the rats, and among them some newly-devoured 

 specimens of the beautiful freshwater shell lo spinosa. The spe- 

 cies most preferred in the Tennessee River was a small clam-like, 

 thick-shelled and corrugated Unio, and it was noticeable that the 

 the same species was by far the most numerous in the shell-heaps of 

 the Cherokees on the river banks. It was rare to find even the 

 most fragile species in these rat-larders broken as if opened forcibly 

 by the rats, a condition the reverse of those obtained in similar de- 

 posits east .of the Alleghenies. 



Genus PEROMYSCTJS Gloger. 



12. Peromyscus leucopus (Raf.). Deer Mouse. 



Compared with specimens from eastern Pennsylvania and New 

 Jersey there appears to be nothing to distinguish the upland Deer 

 Mice of West and Middle Tennessee from typical leucopus. No 

 specimens of this genus were taken in the lowlands of East Tennes- 

 see, but from our knowledge of tlie fauna of that region it is quite 

 certain that the same species is the prevailing form there, associ- 

 ated in certain localities with the Golden Mouse, P. aureolus. I 

 found this species numerous at Raleigh. A few were taken at 

 Saraburg, where they seemed to frequent the intermediate grounds 

 between the overflowed bottoms and the bluff", and at this point their 

 habitat overlapped somewhat that of the large Cane Mouse, P. gos- 

 ■sypinus mississippiensis, described below. 



Two specimens taken at the entrance of Mammoth Cave, Ken- 

 tucky, are identical with those from West Tennessee. 



Specimens — Samburg 6 ; Raleigh, 8 ; Bellevue, 1. 



13. Peromyscus leucopus nubiterrae. Cloudland Deer Mouse. 



Subsp. nov. Type, ad. $ , No. 3,664, Coll. of Acad. Nat. Sci., 



