28. COLUBER 669 
marbled with bright yellow and black. Throat black with 
scattered spots of yellowish orange. About the twentieth 
gastrostege the light color increases in amount and the 
black becomes restricted to small blotches that become fewer 
posteriorly, only a few small, widely scattered spots being 
present on the posterior three-fourths of the body length 
and none on the tail. For most of the length the belly is 
a yellow orange tint, becoming a dark orange tint on the 
posterior one-fourth of the body and on the tail. 
Length to anus_.......... 303 541 723 840 1095 1300 1365 
Lengthvor talle22= 96 185 242 300 345 430 435 
Remarks.—There has long been doubt as to whether 
the black specimens are merely melanistic individuals or 
really represent a distinct species. There seem to be no 
structural differences. Scale-counts and proportions are the 
same. Dark specimens occur in Lower California and on 
Tiburon Island as well as in Arizona. All this favors re- 
garding them as a melanistic phase of the Red Racer, but 
the fact that two black specimens were found mating, near 
Tucson, is very interesting, since it would seem to indicate 
that they may really represent a distinct species. The final 
answer to this question must await additional evidence, but 
it seems best, for the present, to regard the black and the 
red snakes as one species. 
Distribution—The Western Whip Snake or Red Racer 
has its true home in the deserts of Arizona, Nevada, Utah, 
California and Lower California, but ranges into northern 
Sonora (Hermosillo), and the San Joaquin Valley and 
coast region of southern California. 
In California, it has been taken in Imperial (Fort Yuma, 
Colorado Desert, Pilot Knob), San Diego (Mountain 
Spring, Campo, San Diego, Agua Caliente, San Felipe Val- 
