82 SPERMOPHILUS. 



Colohotis. Brandt, Bull. Classe Ph\s — math. Acad. Imp. Scien. 



St. Petersb., 1844, 11, p. 360. 

 Otospermophilus. Brandt, Bull. Classe Phys-math. Acad. Imp. 



Scien. St. Petersb., 1884, 11, p. 379. 

 Otocolobus. Brandt, Bull. Classe Phys-math. Acad. Imp. Scien. 



St. Petersb., 1844, 11, p. 382. 

 Ictidomys. Allen, Mon. Rod., 1877, p. 826. 



Avwiospermophilus. Merr., Proc. Biol. Soc. Wash., 1892, p. 27. 

 Xerospcrmophilus. Merr., Proc. Biol. Soc. Wash., 1892, p. 27. 

 Callospermophilus. Merr., Proc. Biol. Soc. Wash., 1897, p. 189 



(note). 

 Body rather slender; tail either long, moderate, or short, vary- 

 ing greatly in its length among the different species; ears large to 

 rudimentary, not tufted; cheek pouches large; skull variable, short 

 and broad like Sc turns, or long and narrow; postorbital processes 

 strong with a downward direction; anteorbital foramen circular, with 

 a well developed tubercle on outer lower border. 



A. OallospermophiluB. 

 Size large. Skull broad; interorbital space broad; nasals broad 

 longer than premaxillaries; first premolar small. Tail less than half 

 the length of head and body. 



Fig. 17. Spermophilus (Callospermophilus) lateralis. 



No. 2585 Field Columbian Museum Coll. Nat. size. 



Lower tooth row. Upper tooth row. 



Enlarged 4 times. Enlarged 4 times. 



