212 PROCEEDINGS OF THE ACADEMY OF [1897. 



Specimens in the author's collection were taken at the following 

 localities: Eaglesraere, Sullivan Co., 4; Round Island, Clinton Co., 

 3 ; Summit Mills, Somerset Co., 22. Mr. Ingersoll did not find any 

 in the Alleghenies except at Summit Mills, probably more on account 

 of the lack of suitable environment for them in places visited than 

 because this species is not found in the isolated hemlock swamps 

 which yet exist in Juniata, Mifflin and Huntingdon Counties. 



Comparison of a large series of Pennsylvania and northern New 

 Jersey Evotomtjs with series from Quebec shows remarkable external 

 similarity, there appearing no tendency to variation which can be 

 said to be constant. 



14. Microtus peimsylvanicus ^Ord). Wilson's Meadow Vole. 



Abounding in open situations throughout the district up to highest 

 elevatious where food supply abounds. 



A somewhat remarkable color variation in this unusually constant 

 species is found among the fine series taken in Juniata, Huntingdon, 

 Blair and Somerset Counties by Mr. Ingersoll. Nearly all the speci- 

 mens, compared with examples from the New England, New Jersey 

 and eastern Pennsylvania, are noticeably browner, even in the half- 

 grown young. About a dozen of the adults are of two shades of 

 umber-brown over the whole upper parts, two from Tuscarora being 

 almost a deep blackish chestnut. It is somewhat remarkable that 

 all these umber specimens, except one from Bedford County, are 

 females. Other specimens of both sexes taken in the same localities 

 with these do not differ markedly from typical pennsijlvanicus. The 

 cranial characters of the brown specimens seem to belike those from 

 Philadelphia County. 



15. Microtus pinetoruni (,LeC). Pine-woods Vole. 



Occurring in south-central Pennsylvania ; but no specimens have 

 yet come to my notice other than those recorded from Carlisle by 

 Prof. Baird. It has not been found in the higher mountains, nor in 

 the northern counties. 



16. Fiber zibethious ^L.). Muskrat. 



This abundant, and in many cases most destructive of the Rodentia, 

 holds its own in all parts of its extensive habitat. It seems neither 

 to increase nor diminish in numbers, whatever may be the agencies 

 exerted for or against it. 



17. Peiomyscus leucopus (Raf.). Carolinian Deer Mouse. 



This verv common mouse shows but slight variation from the 

 typical form of the Ohio valley, throughout central Pennsylvania. 



