SUBFAMILY SCIURIN^ 143 



5. Thumb large, nail well developed; body thickset; no 



stripes on back Cynomys 



Thumb small, nail rudimentary; body rather slender; 



color pattern variable Citellus 



Subfamily PTEROMYIN^E. 



Genus Glaucomys Thomas. 



Fur soft and thick ; legs connected by a loose skin extending out 

 from the sides of the body ; tail depressed, thickly haired at sides ; 

 ears large; eyes large; postorbital processes narrow, spinelike; 

 rostrum short. 



Dental formula^l. 1/1; Pm. 2/1; M. 3/3=22. 



A single form occurs in Iowa. 



Southern Flying Squirrel. 



Glmicomys volans volans. p. 17 



Subfamily SCIURINyE. 



Genus Sciurus Linnaus. 



Tail long, broad, bushy especially at sides; eyes and ears large; 

 five cla^vs on front feet, the claw on thumb small, and scarcely 

 evident; anterior upper premolar small or wanting; postorl)itaI 

 processes well developed, directed downward and backward; in- 

 fraorbital foramen slitlike and confined to lower -portion of 

 maxillary. 



Dental formula^I, 1/1 ; Pm. 2/1 or 1/1 ; M. 3/3=22 or 20. 

 Key to Species of Sciurus. 



1. General color gray ; color below white or whitish. 



Northern Gray Squirrel. 

 Sciurus carolinensis leucotis. p. 22 

 General color not gray; color below sometimes whitish 

 tinged with rusty 2 



2. Total length 21.00 to 23.00 inches; general color more 

 or less tawny ]1ro^\^l. 



Western Fox Squirrel. 

 Sciurus niger rufiventer. p. 19 



Total length 12.00 to 15.50 inches; general color reddish 



brown. Red Squirrel. 



Sciurus hudsonicus loquax. p, 25 



