1911] Bryant: Horned Lizards of California and Nevada 41 
DISTRIBUTION 
Van Denburgh (1897), in deseribing this form, suggested an 
intergradation with P. b. blainvillei in Santa Barbara or Ven- 
tura counties. In my material this intergradation would seem 
to take place in Los Angeles County. <A series of specimens 
from the northern counties of the state shows distinctly frontale 
characteristies until Los Angeles County is reached. Two speci- 
mens from the northern part of this county (San Francisquito 
Canon, Tuhunga Valley) have equal-sized head scales, very 
much ridged and granulated, which would show them to be 
frontale. Specimens from eastern Los Angeles County (Clare- 
mont) and San Bernardino County are plainly blainvillei, 
having smooth, convex, head scales, those centrally located being 
the largest. All available specimens from the vicinity of Pasa- 
dena, Los Angeles County, however, appear to be intergrades, 
for the head scales are convex, those centrally located being the 
largest, characters of blainvillei, but the scales are ridged and 
granulated, characters of frontale. Sufficient material is not at, 
hand to determine what are the limits of this area of distribution 
in which these subspecies intergrade or to what degree the inter- 
gradation prevails. 
This subspecies is found commonly all through the San 
Joaquin and Sacramento basins and on the western slope of the 
Sierra Nevada. It doubtless crosses over the divide into the 
territory occupied by Phrynosoma platyrhinos in some of the 
lower passes in this range. Specimens of both species have been 
taken on the south fork of the Kern River in Kern County. 
The most northern record for the California horned lizard is 
from Placer County. It meets P. b. blainvillei in Los Angeles 
County. No specimens have been recorded from the coastal 
region north of San Francisco, but southward from this point 
the species is abundant. The type specimen was collected at 
Bear Valley, San Benito County. 
The specimens studied were taken at the following localities: 
Tuhunga Valley, San Francisquito Canon, in Los Angeles 
County; Matilija, Mt. Pinos, in Ventura County; Santa Maria, 
