37+ 3. IGUANIDM 



County. Specimens from other parts of the state vary and 

 seem not to differ materially from this series. We have 

 not found differences to justify the separation of Utah 

 specimens as a distinct subspecies, P. douglassii ornatum, as 

 suggested recently by Stejneger, nor can we find evidence of 

 the occurrence of typical P. douglassii hernandesi within the 

 state of Utah. Utah specimens seem to us to be somewhat 

 intermediate between P. douglassii douglassii and P. doug- 

 lassii hernavulesi, but much closer to the former because of 

 their usually erect occipital horns, which, however, are larger 

 than in typical P. d. douglassii. We believe that the speci- 

 mens from the deserts of northeastern Arizona are like those 

 from Utah. 



Richardson states (Proc. U. S. Nat. Mus., 1915, p. 423, 

 424), that specimens from Deeth, Elko County, Nevada, 

 "all have large reddish head spines and occipitals projecting 

 backward parallel with the temporals, except in one speci- 

 men in which the occipitals are raised at a slight angle", and 

 finds that the Nevada specimens in question represent a 

 race almost intermediate between true Phrynosoma doug- 

 lassii douglassii and the southern form hernandesi. Still in 

 ♦heir larger size and longer head spines they more closely 

 approach the southern form". He therefore records his 

 specimens as Phrynosoma douglassii hernandesi. 



Ruthven and Gaige (Occas. Papers, Mus. Zool. Univ. 

 Mich., No. 8, 1915, p. 23) record Nevada (Carlin, Elko 

 Co.) specimens as Phrynosoma hernandesi and say "The 

 Nevada specimens differ from Utah (Green River) speci- 

 ments in having larger spines, both on head and body and 

 flatter temporal region". They do not state the direction 

 of the occipital spines, but a photograph (pi. V) shows 

 them partially erect. 



As red horns are by no means constantly present in 

 Arizonan specimens of P. d. hernandesi and are frequent in 



