26 MAMMALS OF EASTERN MASSACHUSETTS 



Muskrat; Musquash. Fiber zibethicus (Linne). 



Abundant along streams, lakes, ponds and marshes. 

 This interesting and inoffensive animal, although persist- 

 ently hunted for its fur, still refuses to be driven away by 

 the approach of civilization. A favorite place for them is 

 along the Ipswich River, and in the fall their houses can 

 be seen in process of construction. These houses are 

 composed of mud, sticks and grass, and appear like large 

 mounds. They are built in the grass on the riverbank, 

 with the entrance usually under water and extending 

 upward to a chamber which is above the water line. 

 They vary in height from two to three or four feet. In 

 summer the muskrats live in holes in the banks, where the 

 young are born, usually in May or June. Their fur is 

 greatly in demand, and unless measures are taken to pro- 

 tect them, it will not be long before the species will be a 

 thing of the past in this county. 



Cooper's lemming mouse ; Bog lemming. Synap- 

 tomys cooperi Baird. 



There is no absolute record of this mouse having been 

 taken in the county, but I have included it as without 

 doubt it lives here. The records of their having been 

 taken in the State are at Plymouth and Wareham by Mr. 

 O. Bangs. 1 It is almost never seen and is very difficult to 

 trap. It makes its home in cool sphagnum bogs and 

 swampy woods. Description is as follows: tail very short, 

 color light brown with many black hairs interspersed, 

 some specimens with a slight tinge of reddish brown, 

 others somewhat grayer; ears very short, hidden in the 

 hair; upper front teeth grooved; mammae six. In appear- 

 ance it closely resembles the common field mouse, with 

 which it frequently associates and could easily be taken 

 for it. It can, however, always be recognized by its 

 grooved front teeth. 



lProceedings of Biological Society. Vol. 9, Page 101. 



