140 Ross on the Mammals, Birds, and Eggs 



Order 5. — Rodentia, 



Family SciuRiDiE. 



(Steturinse.) 



Genus Steturus. 



23. Sciurus Hudxonius (Pallas). — Chickaree. Throughout to within the 



Arctic circle. 



Genus Pteromys. 



24. Pteromys alpinus (Rocky Mountain flying Squirrel) (Richardson). 



Found on the mountain ranges of the Liards River. 

 Rather rare. 



Genus Tamias. 



25. Tamias ^warfrm^tof MS (Richardson). — Missouri striped Squirrel, from 



Lat. 83° 30' to 67° worth. Very abundant on the 

 Liards River. 



Genus Arctomys. 



26. Arctomys monax (Gmelin). — Ground-hog. South Carolina to 62° 



North. Rare. 



27. Arctomys pruinosus (Gmelin). — N. to Arctic circle. Abundantinthe 



mountain ranges. 



28. Arctomys Kennicottii (Ross). — This I consider to be a new species, 



but may be wrong. It is of small size, and inhabits 

 the northernmost ranges of the Rocky Mountains. 



(Castorinse.) 



Genus Castor. 



29. Castor Canadensis (Kuhl).— Beaver. Isa of the Chipewyan Indians. 



Throughout North America, to within the Arctic circle; 

 very abundant. 



Family Murid^. 



(Murinse.) 



Genus Jaculus. 



30. Jaculus Hudsonius (Wagler). — Jumping Mouse — Pennsylvania to 



Youcon River. Common at Portage La Sache ; rare in 

 McKenzie's River. 



Genus ffesperomys. 



31. Hesperomys (Gapper) Hamster Mouse. New York to the Arctic 



Sea, very abundant E. of the Rocky Mountains; not found 

 westward on the Youcon River. This species is very 

 annoying in dwellings, as it carries off quantities of sugar, 

 rice, &c. in its cheek pouches, to store them up for its 

 winter consumption. 



Genus Arvicola. 



32. Arvicola riparia (Ord). — Middle States to Arctic Sea. Common. 



33. Arvicola Rickardsonii (Dekay). — 62° north. Rare. 



34. Arvicola xaiithognathus (Leeich). — Red-cheeked Arvicole. North to 



the Arctic Sea. Common. 



