254 Field Museum of Natural History — Zoology, Vol. XI. 



Subfamily ERETHIZONTIN^. 

 Genus ERETHIZON F. Cuvier. 



Erethizon F. Cuvier, Mem. Mus. Hist. Nat. Paris, IX, 1822, p. 436. 



Type Hystrix dorsata Linn. 



Body covered with hair mixed with quills or spines on back and 

 sides, the spines loosely attached to the skin; tail short, thickly spiny 

 and non-prehensile; toes four in front and five behind, armed with 

 strong curved claws; ears short; mammae 4, all pectoral; caecum long; * 

 the gall bladder apparently absent; skull with facial portion short; 

 a horizontal process of the maxillary extends outward, joining the 

 zygoma forming a large antorbital vacuity and having the appearance 

 of a second zygoma (see fig. 6, p. 96); auditory meatus with protrud- 

 ing edge; crowns of molars with enamel folds and more or less com- 

 pletely rooted; tibia and fibula separate and not anchyloscd below. 



Dental formula: I. ^-"-> C.^-^. Pm. ^—^, M.^-^=20. 

 i-i 0-0 i-i 2>-i 



Erethizon dorsatum (Linn.). 

 Canada Porcupine. 



[Hystrix] dorsata Linnaeus, Syst. Nat., X ed., I, 1858, p. 57. 



Hystrix Hudsonius Lapham, Trans. Wis. State Agr. Soc, II, 1852 (1853), p. 340 

 (Wisconsin). Haymond, Rept. Geol. Surv. Ind., 1869, p. 208 (Indiana). 



Erethizon dorsatiis Kennicott, Agr. Rept. for 1857, U. S. Patent Office Rept., 1858, 

 p. 91 (Illinois, Indiana). Miles, Rept. Geol. Surv. Mich., I, i860 (1861), p. 221 

 (Michigan). Herrick, Geol. & Nat. Hist. Surv. Minn., Bull. No. 7, 1892, p. 246 

 (Minnesota). Evermann & Butler. Proc. Ind. Acad. Sci., 1893 (1894), p. 125 

 (Indiana). 



Hystrix dorsata Strong, Geol. Wis., Surv. 1873-79, 1883, p. 440 (Wisconsin). 



Erethizon dorsatum Adams, Rept. State Board Geol. Surv. Mich., 1905 (1906), p. 129 

 (Michigan). Jackson, Bull. Wis. Nat. Hist. Soc, VI, 1908, p. 24 (Wisconsin). 

 Hahn, Ann. Rept. Dept. Geol. & Nat. Resources Ind., 1908 (1909), p. 530 

 (Indiana). Evermann & Clark, Proc. Wash. Acad. vSci., XIII, 191 1, p. 2 

 (Indiana). 



Type locality — Eastern Canada. 



Distribution — At present, northern North America south to Maine, 

 the mountains of Pennsylvania, northern Michigan, Wisconsin and 

 Minnesota. Formerly its range extended south to Indiana. 



Description — Hair on upper parts mixed with quills or spines ; general 

 color dark brown to nearly black, often mixed with yellowish white 

 hairs; hair of upper parts long, nearly or quite concealing the quills 



* Beddard gives the length of the cscum in Erethizon as 2 feet 4 inches (Mam- 

 maHa, 1902, p. 499). 



