REVISION OF THE PUMAS 579 



series, with a detailed table of measurements of the skulls, will 

 be found under the species to which they belong — Felts hippo- 

 lestes. It may be stated here however that the limits of varia- 

 tion for adults of each sex fall within surprisingly narrow 

 bounds. This points toward stability in the characters presented 

 by other species of the group. In this connection I may be 

 permitted to state what I believe to be a general law (confirmed 

 by critical studies in most groups of North American mammals), 

 namely, that completely differentiated types (specific or sub- 

 specific) from the areas where the typical forms occur, show 

 relatively little individual variation, while the intergrades con- 

 necting such types, and also local forms not yet completely 

 established, show a wide range of individual variation. 



Specific characters in some groups are shared equally by the 

 two sexes, but this is not the case with the Pumas, for these 

 animals conform to the rule among the Carnivora that the male 

 is the larger and more highly developed. The male Puma is 

 much larger and more powerful than the female, the skull and 

 teeth are much larger and more massive, and, what is still more 

 important, the male alone attains complete specific differentia- 

 tion. By this is meant that the distinctive cranial characters of 

 the various forms are onl}^ fully developed in the males, skulls 

 of females resembling each other so closely that in several cases 

 they are distinguished with difficult}' . 



While the skulls of the several members of the group bear a 

 strong general resemblance to one another, marked differences 

 exist, chiefly in the proportions of the several parts. The most 

 conspicuous of these are in the degree of elevation or depres- 

 sion of the face and frontal region, the extremes of which are 

 presented by Fclis -patagonica of the Southern Andes and F. 

 olyinpus of the Puget Sound region. In Fclis patagonica the 

 skull is long and low, the face slopes strongly backward, the 

 orbital process of the jugal rises only slighth^ above the body of 

 the bone, the frontal region is depressed and flattened, and the 

 highest part of the cranium is behind the postorbital processes. 

 In F. olyniptis the face rises abruptly, the orbital process of the 

 jugal rises strongly and suddenly, the frontal region is highly 

 elevated and swollen, and the highest part of the cranium is in 



