78 REPORT OF NEW JERSEY STATE MUSEUM. 
1900, Mr. J. von Lingerke described the presence of a colony of 
beavers in Sussex County, which had apparently escaped from a 
private preserve where they had been introduced. At any rate 
they were firmly established at that time. 
Castor canadensis Abbott, Cook’s Geol. N. J., 1868, p. 757.— 
von Lingerke, Forest and Stream, 1900.—Rhoads, Proc. Acad. 
Nat. Sci. Phila., 1897, p. 29. 
Castor canadensis carolinensis Rhoads, Mam. Pa. and N. J., 
1903, D- 73- 
Family SCIURIDZ. 
SQUIRRELS AND MARMOTS. 
This family comprises animals which are on the average larger 
than the Muride, very active and intelligent and usually hand- 
some, with graceful, more or less bushy tails. Some species are 
fossorial, while others are arboreal, and one, the flying squirrel, 
is not only arboreal but aerial, curious “parachutes” being devel- 
oped between the legs. The several genera found in New Jerse 
may be separated as follows: 
a. Body large. MARMOTTA (Ground Hogs) 
aa. Body less than fifteen inches in length. 
b. No extensible flying membrane on the sides of the body. 
c. Tail short, only one-third to one-half the length of head and body. 
d. Color uniform gray. CITELLUS (Spermophiles) 
dd. Back striped. TAMIAS (Chipmunk) 
cc. Tail long and bushy. scturus (Squirrels) 
bb. An extensible fold of skin on the sides of the body for flying. 
SCIUROPTERUS (Flying Squirrel) 
Genus MArmMoTra Zimmerman. 
W oodchucks. 
Marmotta monax (Linnzus). 
Woodchuck, Groundhog. 
PLATE 33: 
Length 24 inches. Heavy and thick-set, legs short, tail rather 
short and bushy. Color grizzly or yellowish gray varied with 
black and rusty, under parts rusty, feet black. 
