16 THE JOURNAL OF THE 



' Generally rare, although said to occur not unfrequently in 

 certain localities in Eastern Massachusetts. Mr. J. W. P. 

 Jenks of Micldleboro has taken quite a number in that 

 place,* and Mr. J. A. Allen states that there are several 

 specimens from the neighborhood of Cambridge, Mass., 

 in the Museum of Comparative Zoology.f 



13. Arvicola rip aria Ord. Field Mouse. An abun- 

 dant species; at times exceedingly so. It often proves 

 itself very injurious by girdling apple and other fruit 

 trees, as well as young pitch pines {Pinus rigida Linn.) 



This species is generally more abundant after a winter 

 in which there has been a great deal of snow, as they are 

 kept warm thereby and few consequently perish from the 

 cold. After an open winter they generally decrease, as 

 the burrows are too shallow to protect them from being 

 frozen. They occur almost everywhere from the most 

 sandy fields to swampy meadows. In hay-fields the Field 

 Mouse forms burrows extending for a considerable dis- 

 tance under the roots of the grass. Its habits however 

 vary with circumstances. In grain fields it extends its 

 burrows beneath the surface. 



There are said to be at least three litters raised in a 

 season, and nests are often found with yonng mice in them 

 irom May until October or ]Srovember. The light variety 

 of this species, described by Prof. S. F. Baird, under the 

 name of Arvicola hreweri^ J has been found by Mr. Allen 

 at Muskeget Island and at the Ipswich Sand-hills. 



14c. Arvicola pinetorum And. and Bach. Pine Mouse . 

 The occurrence of this rare species in this state, is based 

 on two specimens taken in May, 1868, at Springfield, 

 Mass., by Messrs. E. and J. A. Allen. It is more abun- 

 dant farther south. 



* Baird: N. Am. Mam. p. 521. 



t Bull. Mus. Comp. Zool. Vol. 1, No. 8, p. 231. 



X N. Am. Mam. pp. 525-526. 



