RODEiNTIA. HYSTRICID^. 71 



1. Hyslrix dorsata. Lin. Gmel. The Porcupine. 



Hystrix Hudsonius, Briss., 128. 



Hystrix dorsata, Harlan, Fauna Am., p. 190. 



The Canada Porcupine, Godman, Nat. Hist., ii. p. 150. 



Hystrix pilosus, Richardson, Fauna Bor. Am., p. 214. 



Figure ; Godman, ii. p. 150, f. 2. Griffith's Cuvier, iii. p. 206. 



Specific characters. Color black ; body covered with coarse 

 hair, intermingled with pointed spines, whose shafts are white, but 

 their ends or tips are black ; tail thick, prehensile, and ancipital ; 

 nails long, and moderately curved. 



Description. The general color is somewhat various ; it is 

 black, or brownish black ; hmbs robust ; quills upon the head and 

 extremities short and stiff ; those upon the back long ; many 

 short ones intermingled with the hair all over the animal ; neck 

 thick, belly large, and limbs nearly equal in length ; nose obtuse ; 

 molar teeth of the upper jaw inclining outwards ; those of the 

 lower inwards ; each set or line standing in an angular direction ; 

 crowns flat ; each molar of the upper jaw presents a single sulcus 

 on the inside, deeper and more strongly marked in the first and 

 last ; the outside presents three sulci separated by double lines of 

 enamel, or a plate of enamel folded on itself; the lower molars 

 resemble the upper, except that the arrangement of the sulci is 

 reversed, the single deep sulcus appearing on the outside, and the 

 three which constitute the principal grinding surface, on the inside ; 

 there are no lateral grooves as in the teeth of the Beaver ; the 

 grinders wear posteriorly, the jaw admitting of motion principally 

 from before, backwards, or the reverse. 



Dimensions. 



ft. in. t'tha. 



Whole length, 220 



Tail, 075 



Height of the back, . ^ 12 



Skull. 

 Length from the nasal to the occipital spine, . . . .039 

 From the insertion of the incisors to the foramen magnum, 3 8 



Heigiit of the upper jaw, 16 



Width of the top of the skull over the eyes, . . . 14 

 Longest spines, 025 



