IIO MAMMALS OF PENNSYLVANIA AND NEW JERSEY. 



they find their danger is from above the grass they soon learn to skulk rather 

 than leap. I have been unable to trap this rodent after the first few killing 

 frosts, these being the signal for retiring into some snugly prepared corner 

 where they may curl into a spherical shape within a spherical nest of leaves 

 and grasses and sleep until frost departs again. This hiding place generally 

 seems to be placed far enough beneath ground to escape freezing in this lati- 

 tude. I know of no food provision being made for winter as with the chip- 

 munk. In fact they would be helpless to use it, as a freezing temperature 

 soon begins to stupefy them. Abbott states they appear to store up chinka- 

 pins for future use in November. They can be thawed out and frozen again 

 artificially several times before they succumb to this inhuman treatment. 

 When going into winter quarters they are excessively fat, as I can testify from 

 experience in removing this tenacious yellow blanket from the skins of them. 

 This fat is their fuel. By spring it is nearly gone. Their natural food I have 

 not been able to certainly identify. It is stated by some to be buds, seeds, 

 nuts and grasses. They eat corn and oatmeal bait from my trap. It is 

 likely they may devour a good many insects, for capturing which their agility 

 would eminently fit them. Inquiry along these lines might show this animal 

 to be one of the most useful (as it certainly is one of the least destructive) 

 of our small rodents. Abbott says they eat but little grain and are too scarce 

 to do any harm even if they had that failing. 



Description of species. Species of this genus may be known from all other 

 American mice by their having a body the size of a house mouse with long, 

 slender, almost naked tail, which is i^ times as long as head and body. The 

 hind foot, in its great relative size to length of body, is also distinctive. 

 The head is very small and the slender front teeth have a distinct groove 

 running down the face of each, in this respect resembling the little harvest 

 mouse (Reithrodontomys), a species we do not find in Pa. and N. J. Zapus 

 hudsonius is to be distinguished from Z. h. americanus, the next form to be 

 considered, by its larger size and the better defined, dark dorsal stripe in 

 contrast with the color of sides. In hudsonius the upper colors are yellowish- 

 brown, with sides light grayish-buff, lightly sprinkled with black. In ameri- 

 canus the back is dusky-brown, tinged with reddish -buff, sides reddish-buff. 

 Both are snowy white beneath. Both forms of these meadow or open-ground 

 Zapus may be known externally from the woodland, Naptzozapus, by grayer 

 color, smaller size and the lack of a white tip or terminal part of the tail. 



Measurements. {hudsonius} total length, 220 mm. (8J/2 in.); tail verte- 

 brae, 130 (5>); hind foot, 31 (i^.) {americanus} 190 (7^) ; 115 (4^) ; 

 18 (i^). 



Barton's Zapus, or Meadow Jumping Mouse. Zapus hudsonius 

 americanus (Barton). 



