KKY TO LAND MAMMALS OF NORTHEASTERN NORTH AMERICA QI 

 SUBSPECIES OF SCICROPTEBUS SABBINUS 



Size large, hind foot over 40 (lA) ; ear short and 



broad S. sahrinus sabrinus 



Size medium, hind foot under 40 (Ii'b) ; ear long 



andnarrow S. sabrinus maorotis 



Sciuropterus sabrinus sabrinus (Shaw) Hudsonian flying squirrel 



1801 Sciurus sabrin u s Shaw, Gen. zool. 1 : 157. (Severn river, James bay) 

 1898 Sciuropterus sabrinus Mearns, Proo, U. S. nat. mns. 4 Nov. 1889. 

 21: 353. 

 Total length, 350 (13i) ; tail vertebrae, 140 (5i) ; hind foot, 42 (IJJ) ; ear from 

 crown, 15 (|). (sabriuus; N. Lat., Severn) 



The Hudsonian flying squirrel is confined to the Hudsonian forests of 

 eastern and central Canada. 



Sciuropterus sabrinus macrotis Mearns Canadian flying squirrel 



1896 S ciur o p t er u s sabrinus Bangs, Proo. biolog. soe. Washington. 



28 Dec. 1896. 10 : 162. 

 1898 Sciuropterus sabrinus macrotis Mearns, Proo. U. S. nat. mus. 



4 Nov. 1898. 21: 353. (CatskiU mts, N. Y.) 



Total length, 280 (11) ; tail vertebrae, 125 (5) ; hind foot, 38 (IJ) ; ear from 

 crown, 20 (f). (macr6tis; Gk., long eared) 



The Canadian flying squirrel is abundant in the Canadian forests of 

 the northeastern United States and southeastern Canada. 



Family Castoridae Beavers 



Four broad, rootless cheek teeth in each jaw; angle of lower jaw rounded; 

 tail very Iroad, flattened from above downward, scaly ; size large. (Cast6ridae; 

 genus Castor) 



The family Castoridae is represented by a single living genus 

 common to the northern parts of both old and new worlds. 



Genus Castor Linnaeus 



1758 Castor Linnaeus, Systema naturae, ed. 10. 1 : 58. Type Castor fiber 

 Linnaeus. 

 Feet four-toed; hind feet webbed; second toe of hind foot double-clawed. 

 (Cdstor; Lat., a beaver) 



One species of beaver occurs in North America. It is closely related 

 to that of the old world. 



