1924] GrinneU-Dlxon: The Genus Lynx in Calif ornui 341 



amount and degree of softness of pelage, general tone of color, extent 

 of dark markings relatively to light markings, general elongation of 

 skull as compared witli a condition of roundness of skull, and degree 

 of development of ridges on the skull. 



External variations. — As far as we are aware, there are in the 

 wildcat no ''phases" of coloration ("gray" versus "red") com- 

 parable with those in the mountain lion. There is, however, remark- 

 ably great seasonal, on top of individual, variation, bringing almost 

 as great extremes of color tone. There is but one molt a year, taking 

 place in the fall, August to October, inclusive. Just after the comple- 

 tion of this annual molt, the pelage is, of course, prime and shows its 

 really intrinsic colors. But very shortly, even by February, noticeable 

 changes have begun to take place, and these lead to the summer con- 

 dition where the animal is of a more or less different, yellowish or 

 reddish cast of color. 



There is every reason to believe that this change in color tone is 

 caused by continued exposure to wear and to the light, particularly to 

 sunlight, M-hether direct or reflected. For the yellowest or reddest 

 pelts are those taken from animals in mid or late summer, in open 

 country in the dry cloudless interior. It is to be noted, on the other 

 hand, that summer pelts from regions of forest or heavy chaparral, 

 or from the coastal fog belt, show relatively little of this adventitious 

 change of color tone. 



We have, in illustration of this variation of color tone, an extreme 

 example of Lynx ruffus calif ornicus in summer pelage (no. 2333, Mus. 

 Vert. Zool., adult male) trapped on rocky and sparsely bushy ground 

 on the desert slope of the Santa Rosa Mountains, 3000 feet altitude. 

 Riverside County, June 20, 1908. The general tone of color is pinkish 

 buff, obscured with dusky down the middle of the back. The spotting 

 along the sides of the body and down the outsides of the legs is indis- 

 tinct and approaches bright cinnamon in color. The sharp spots on 

 the chest and belly and on the insides of the legs are not jet black 

 but are of a dusky drab to blackish brown tone ; this is true also of the 

 dark markings on tlie face, ears, and tail. The pelage all over, though 

 particularly so on the back and sides of the body, is much shorter and 

 seemingly sparser than in winter pelts. This condition is obviously 

 due to the wearing off of the ends of the overhairs, perhaps in part 

 also to the dropping out of many of the overhairs, entire. As a result, 

 much more of the tawny-hued underfur is left exposed and, moreover, 

 the original tawnv tone of this underfur has faded out to a buffv tint. 



