26 University of California Publications in Zoology {[Vou.9 
(P. douglassi pygmaea), P. douglassi hernandesi and P. douglasst 
ornatissimum. The first is found only in the North Pacifie dis- 
trict, the second only through the central district, the Rocky 
Mountains and Great Basin, and the third, the desert species, 
only on the deserts east of the Sierra Nevada. P. douglassi 
douglassi is much smaller than the other subspecies and may be 
distinguished also by its very blunt snout, its very rudimentary 
horns and its inconspicuous color. Cope (1898) suggests that 
the characters define races which do not seem to be sufficiently 
distinct to represent subspecies. 
The first description of this species was made by Bell (1828) 
from a specimen collected in Washington by H. W. Henshaw. 
Yarrow (1882, 1887) gave specimens from the same locality the 
subspecifie name of pygmaea on account of their small size. This 
name, however, had to give way to that of dowglasst when the 
subspecies were fully worked out by Stejneger (1890) and Cope 
(1898). 
Hasirs 
Bell (1828) states that these horned lizards are always found 
in the immediate vicinity of water. If this be true, P. douglassi 
douglassi is different from other members of the genus, for most 
Phrynosomas depend upon the drops of dew on the vegetation for 
their water. It is also stated by the same author that this sub- 
species lives partly on the surrounding vegetation. This would 
seem another exception to the general rule, for all the species 
studied were found to be strictly imsectivorous. These two 
observations need verification. 
The protective coloration assumed by this species is very 
interesting. All shades and colors from the obscure gray skin of 
P. douglassi douglass: to the brightly spotted skin of P. douglasst 
ornatissimum are to be found. Indeed the character of the 
coloration is so modified by the environment that it is found 
constant enough to act as one of the characters for distinguishing 
subspecies. The large P. douglassi ornatissimum resembles the 
vari-colored rocks of the Painted Desert of Arizona where it is 
found, whereas P. douglassi douglassi resembles the gray uni- 
colored soil on which it occurs. 
