_Remarks._--Skulls of martens from many localities in western North America were studied in an effort to determine the relationship of the eastern pine marten (_Martes americana_) and the western marten. East of the Rocky Mountains the ranges of the two species approach closely, but each retains distinctive characters, notably the shape of the auditory bullae. The two species have not been taken together and the possibility of intergradation exists. On the basis of the evidence at hand, the two should be regarded as full species until positive proof of intergradation is established. In the absence of sufficient material, the marten of the Cascades is referred to _Martes caurina caurina_. Fur graders distinguish between a dark "coast marten" and a paler "Cascade marten." =Martes caurina origenes= (Rhoads) _Mustela caurina origenes_ Rhoads, Proc. Acad. at Sci. Philadelphia, 1902:458, September 30, 1902. _Martes caurina origenes_ Miller, U. S. Nat. Mus. Bull., 79:93, December 31, 1912. _Type._--Obtained at Marvine Lodge, Garfield County, Colorado, by E. T. Seton on September 16, 1901; type in Academy of Natural Sciences of Philadelphia. _Racial characters._--Paler than _caurina_ with grayer head and yellow or white rather than deep orange or brown throat patch. _Distribution._--Mountainous areas of northeastern Washington and the Blue Mountains of southeastern Washington. Trappers have reported this marten from the mountains near Republic, Ferry County. =Martes pennanti= (Erxleben) Fisher [_Mustela_] _pennanti_ Erxleben, Syst. Regni. Anim., 1:470, 1777. _Martes pennanti pennanti_ Miller, U. S. Nat. Mus. Bull., 79:94, December 31, 1912. _Mustela canadensis pacifica_ Rhoads, Trans. Amer. Philos. Soc., n.s., 19:435, September, 1898 (type from Lake Keechelus, Kittitas County, Washington). _Martes pennanti pacifica_ Miller, U. S. Nat. Mus. Bull., 79:94, December 31, 1912. _Martes pennanti_ Grinnell, Dixon and Linsdale, Fur-bearing Mamm. California, Univ. California Press, Berkeley, p. 211, July 22, 1937. _Type locality._--Eastern Canada. _Distribution._--Originally forested areas from the eastern base of the Cascades westward and possibly the Blue Mountains of southeastern Washington and the mountains of northeastern Washington; now probably confined to the Cascade and Olympic mountains. [Illustration: FIG. 54. Fisher (_Martes pennanti_). 2-year-old male in captivity; New Westminster, B. C., March 7, 1939. (Fish and Wildlife Service photo by Victor B. Scheffer, No. 598.)]