344 University of California Puhlications in Zoology [Vol. 21 



bigness of males; males are roughly one-fourth larger than females. 



With respect to purel.y individual variation in cranial characters, 

 our material shows that there is undoubtedly some range, involving, 

 among other features, degree of inflation of auditory bullae and size 

 and shape of teeth, but just how much relatively to that in other 

 carnivores we are unable to say. Our impression is that there is 

 rather less than with, say, the bears or coyotes. If, then, the sex and 

 comparative age of a skull is known, the characters which it presents 

 can be pretty well relied upon in determining its racial status, pro- 

 vided comparable specimens of other subspecies are available as 

 standards of comparison. 



Geographic variation. — Having disposed of some facts and infer- 

 ences concerned with other modes of variation, we can now proceed 

 to a discussion of that mode of variation which relates geography 

 to evolution. The trend of variation geographically in the wildcats of 

 California, from the humid coast belt to the arid interior, is as follows : 

 As to coloration, from dark-toned, heavily marked, to pale-toned, 

 lightly marked; as to pelage, from relatively short, with overhairs 

 coarse, to full and very soft throughout ; as to skull, from smaller, 

 rounded cranium Avith weak development of ridges, in the southern 

 coast district, to larger, elongated cranium, prominently ridged, in 

 the Modoc region (part of northern Great Basin fauna! province). 

 (See plate 11.) Among the races recognized by name below, the 

 greatest contrast in general size is afforded b.y calif orniciis and 

 pallescens, in size of ear by fasciatus and haHeyi, in fulness of pelage 

 by californicus and pallescens, in softness of pelage by fasciatus and 

 pallescens, in depth of color and boldness of dark markings by 

 fasciatus and iaileyi, in size and shape of skull by californicus and 

 pallescens. (See map, fig. A.) 



Our conclusion that there are four, rather than three or five or 

 seven, conveniently recognizable subspecies of the wildcat in Cali- 

 fornia is based upon what at this writing we consider a conservative 

 point of view. It is true that, after appropriate appraisement of the 

 other modes of variation, certain geographic peculiarities are seen to 

 pertain to the wildcats of the western slope of the central Sierra 

 Nevada as compared with those of the San Diegan district (we include 

 both in californicus) ; to the wildcats of the lower portions of the 

 Colorado Desert as compared with those of the more elevated central 

 and eastern portions of Arizona (we put both lots under haileyi) ; 

 and to the wildcats of the Humboldt Bay district as compared with 

 those from the humid Pacific coast belt farther to the northward 



