1894.] NATURAL SCIENCES OF PHILADELPHIA. 391 



vauia aviericanns aud New England examples of S. a. canadensis. 

 Their longer tails and lack of a distinct dorsal stripe indicate this. 



The Pocono mice are of a more uniform and much duller brown 

 on the upper parts than soutt Pennsylvania specimens, and in old in- 

 dividuals there is no trace of the dusky dorsal stripe which is so 

 pronounced in specimens from New Jersey and New England. 

 Specimens from Pike County match one in the collection from Lome 

 Park, Ontario, and three from Clinton County, Pennsylvania. 



14. Fiber zibethicus L. Muskrat. 

 Not abundant. 



15. Arvicola pennsylvanicus (Ord). Common Meadow Mouse. 

 Abundant, and constant to its typical characters in all situations. 



16. Arvicola pinetorum (LeConte). Pine Mouse. 



A specimen taken at Yaggie's farm, and another at Porter's Lake 

 attest the semiboreal range of this southern species. 



17. Evotomys gapperi (Vigors). Eed-backed Mouse. 



A rather rare species. Four captures were made at Yaggie's in 

 the more heavily timbered swamps. This animal does not appear to 

 confine its operations to runways or underground as does the true 

 Arvicola, but forages about like Sitomi/s in more open situations at 

 the surface. 



I took none at Dingman's Ferry, and am of the opinion they are 

 not found much below an altitude of 1,000 feet in Pike County. 



18. Synaptomys cooperi Baird. Cooper's Lemming Mouse. 



One of these highly interesting rodents was captured in a meadow 

 bordering the Bushkill, on Yaggie's farm. It was taken in a 

 "cyclone trap," set in the runways of Arvicola pennsylvanicus, near 

 the edge of a dry swamp. A specimen of the latter species was 

 subsequently taken in the same spot. This is the first authenticated 

 record for Pennsylvania of Cooper's mouse, though it is not improb- 

 able that the tyge was taken within fifty miles of this place, either on 

 that or the New Jersey side of the Delaware. 



This, together with recent captures in New England and eastern 

 Canada, may now be considered sufficient to fix the type habitat of 

 Cooper's mouse east of the Alleghany Mountains, rather than west 

 of them as was once considered possible, owing to the total lack of 

 recorded eastern specimens. 



