6. CROTAPHYTUS7. UMA 131 



tat. They are found living in abandoned burrows of the 

 Kangaroo-rat, Perodipus. All the stomachs examined con- 

 tained grasshoppers." 



Genus 7. Uma 



Uma BAIRD, Proc. Acad. Nat. Sci. Phila., 1858, p. 253 (type, no fata). 



The head and body are moderately depressed, not much 

 shorter than tail. The snout is rounded when seen from 

 above but pointed in profile. The head plates, including 

 the interparietal, are small, the largest being smaller than 

 the ear-opening. The supralabials and superciliaries are im- 

 bricate. The dorsals are small and nearly uniform. The 

 ear-opening is large, with a strong anterior denticulation on 

 a valve like dermal flap. There is a strong gular fold. A 

 long series of femoral pores usually with a second, shorter 

 series, present. There is a series of elongate scales project- 

 ing from each side of the digits and from the external side 

 of the sole of the foot. 



Four species have been described, but there can be no 

 doubt that all are based upon individual, sexual and age 

 variations of a single species. 



Some authors have preferred to unite the genera Uma 

 and Callisaurus, but the small size of its interparietal plate, 

 the large anterior ear scales, the dermal ear valve, the 

 greater development of the spines on its toes, the normal 

 duplication of its series of femoral pores, and its different 

 style of coloration seem to justify the retention of the genus 

 Uma. 



