78 
NEW-YORK FAUNA. 
in length from half an inch to three inches, and are white with black tips, or entirely white. 
When examined with a lens, they are found to be covered with minute barbs, imbricated, and 
pointed towards the base. On the crown of the head and neck, these are short, thick and 
numerous ; on the shoulders and anterior part of the back, they are few, slender and flexible ; 
on the posterior part of the back, and on the thighs, they are very long, strong and numerous. 
The upper part of the tail is also furnished with smaller spines. The young have long white 
hairs in place of spines. 
Teeth. In the upper jaw, the incisors are very strong, flattened in front abruptly, and bevelled 
behind ; the portion within the sockets three-sided, nearly two inches long, describing the 
segment of a circle nearly two inches in diameter ; the bottom of the.socket reaches beneath 
the socket of the posterior molar. The first, third and fourth molars-nearly equal, the second 
smallest. The anterior molar with three large and irregular diverging prongs, of which the 
internal is broad and largest; the crown with five cavities separated by waving plates of 
enamel, the posterior exterior cavity smallest, oval. The second molar small, with four 
cavities on the crown, resembling in shape the two posterior molars ; but the internal oblique 
cavity becomes gradually effaced in 'the posterior molar, by the absence or rather subsidence 
of the internal wall. The fangs of this second molar are also three in number, with a tendency 
in the two outer to become double ; in the two last, the prongs are increased to three. In the 
lower jaw, the incisors are 2 '7 long, and reach beneath the root of the posterior molars ; they 
project farther from the jaw than those of the upper jaw, and describe an arc of a larger circle ; 
the bevelled portion is also much longer. The molars are similar in size and configuration 
above, except the second, which is smaller. They have all four cavities, three of which are 
regularly bounded by plates of enamel, and the external cavity deficient on its outer margin. 
The anterior molar with three prongs, of which the anterior is largest; the whole periphery 
of the crowns surrounded by a plate of enamel, including the plates which bound each cavity. 
With age, the whole surface is ground down, leaving no vestige of cavity. The molars of 
the upper jaw incline outwards ; of the lower, inwards. 
Color. Usually dark brown, intermixed with black ; the females are said to be of a darker 
brown. They are often hoary, and occasionally entirely white. The tail is brown above and 
beneath, with a few whitish hairs along its margin and at its tip. 
Length of head and body,.. 24 ■ 0. 
Ditto of the tail,. 6‘0. 
Ditto of the skull,. 4 - 0. 
The Porcupine is an inoffensive animal, and very gentle in its manners. It feeds on the 
leaves and bark of the hemlock (Pinus canadensis), the basswood (Tibia glabra), and the ash 
(Fraxinus sambucifolia). It is also fond of sweet apples, maize, and will scarcely refuse any 
vegetable offered to them in confinement. They move very sluggishly, dragging their tail on 
the ground. When irritated, they make a faint whining noise, and by a strong cuticular 
muscle the spines of the back and sides are erected and extended in various directions ; the tail 
