568 U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



ERETHIZON, F. Cuvier. 



Erethizon, F. CUVIER, M&n du Mus. IX, 1822, 426, 432. 



For the principal characters of the skull and teeth, I would refer to the diagnosis of the family 

 Hystricidae and sub-family Cercolabinae. In distinction from Cercolabes, the tail is short, 

 thick and depressed ; covered above at the base with hairs and spines, at the apex and on the 

 under surface with stiff bristles. Nostrils closely approximated. Feet short and broad. Toes 

 (4, 5,) all armed with long and curved claws. 



The genus Erethizon is confined to North America, extending, perhaps, into Mexico on the 

 south, and ranging to the parallel of 67 on the north, and from the Atlantic to the Pacific. 

 It is very closely allied to the South American and Mexican Cercolabes, but is readily distin 

 guished by the much shorter and stouter tail, which is well covered with hairs and spines, and 

 is incapable of prehension. The nostrils are more approximated, being separated by an 

 extremely narrow partition. The anterior molar is usually considerably larger than all the 

 others. 



The hind feet differ in having a distinct inner toe, which is armed with a large claw ; the 

 feet lack the projecting semi-circular lobe on the inner side, seen in Cercolabes. The naked soles 

 are covered with minute tubercles. The upper lip is slightly notched above the incisor teeth, 

 but there is no dividing groove, or naked mesial line, as in the Old World porcupines ; even 

 the narrow septum between the nostrils is not destitute of hairs. The body is stout, and 

 covered on the upper parts with a long and dense fur, which hides the spines. The limbs are 

 short and strong. 



The most important differences between Erethizon and Hystrix will be found detailed in the 

 characters of the sub-families to which they respectively belong. 



ERETHIZON DORSATUS. 



White Haired Porcupine. 



Hystrix dorsata, LINN. Syst. Nat. (ed. 10) i, 1758, 57. IB. (ed. 12) I, 1766, 76. 

 EBXLEBEN, Syst. 1777, 345. 



BODDAERT, El. Anim. I, 1784, 128, (from Pennant.) 

 GMELIN, Syst. Nat. I. 1788, 119. 

 SCHREBER, Saugt. IV, 1792, 605 ; tab. clxix. 

 SHAW, Gen. Zool. Mamm. II, 1801, 13 ; pi. cxxv. 

 KUHL, Beitrage, 1820, 70. 

 DESMAREOT, Mamm. II, 1822, 345. 

 COZZENS, Ann. N. Y. Lye. I, i, 1823, 191, (habits.) 

 HARLAN, F. Am. 1825, 190. 



GRIFF. Cuv. in, 127, 206, original fig. IB. V, 1827, 263. 

 FISCHER, Synopsis, 1829, 368. 

 ATJD. & BACH. N. Am. Quad. I, 1849, 278 ; pi. xxxvi. 



