CLASS I. MAMMALIA: ORDER 7. RODENTIA. 



401 



The Long-tailed Atherure, A. macrurus, the Hystrix Orientalis of Brisson, is found in Ma- 

 lacca; it is smaller than the preceding, but has been only obscurely described. The A. Afrkanus, 

 is of Fernando Po, and the A. armatus of Gambia. 



SWINDER S AULACODE. 



Genus AULACODE : Aulacodus. — Of this there is a single species, the Ground-Rat or Swin- 

 der's Aulacode, A. Swinderianus : this is of the size of a rabbit, of a brown color, with short legs 

 and a long body, covered with short spines of nearly uniform length. The tail, of medium length, 

 is covered with similar spines. A specimen has been furnished from Sierra Leone to the London 

 Zoological Gardens. It is found on the western coast of Africa, and also in Southern Africa. 



Genus ERETHIZOX: Erethizon. — Of this there is a single species, the Canada Porcupine, 

 E. dorsatus ; the Hystrix Hudsonii of Brisson; the Urson of Buffon, and the only animal of the 

 family of Hystricidce found in North America. In this the ears are short and hid in the fur: 

 head, body, legs, and upper part of the tail covered with rather coarse, long, dark-brown hair; on 

 the upper part of the head, back, body, and tail, a dense mass of sharp, strong quills, the longest 

 on the back, the least toward the head and sides; the longest four inches, but all nearly hid in 

 the hair. Intermixed are some stiff, straggling hairs, three inches longer than the rest, tipped with 

 dirty white; under side of the tail white; four toes on the fore-feet, five behind, each armed with 

 long claws, hollowed on their under side. The form of the body is very clumsy, resembling that 

 of a beaver, but in size it is smaller, averaging from twenty-four to thirty inches. The color, also, 

 is subject to great variations, the long hairs on the sides, shoulders, and forehead being sometimes 

 of a yellowish-brown, and sometimes of a dirty white. In most cases, however, it aDDears that 

 the hips and under-surface of the tail, as well as the body, are a blackish-brown. 



The great peculiarity of this animal consists in his spines, or quills, which are cylindrical in 

 shape, sharp at the extremity, and pointed at the root. They are very easily detached, and. are 

 erected at pleasure. They are barbed with numerous reversed hooks or prickles, which, when 

 »)nce the shaft is imbedded in the flesh, constantly work deeper and deeper into it. The spines 

 ire from one to four inches in length, the longest on the back as above stated. They cover the 

 vhole upper surface, the under surface being clothed with hair, intermixed with fur of a softer 

 exture. In old animals, the whole body above is a mass of spines, with tufts of hair six inches 

 'ong on the shoulders, sides, and forehead. The eyes are small, the tail short, and covered above 

 Vol. I.— 51 



