Revision of the Coyotes. 21 



Geographic Distribution and Interrelations. 



The material available for the present study is insufficient to 

 admit of mapping the boundaries of tlie areas inhabited by the 

 several forms, of describing the seasonal differences in pelage, or 

 of determining which members of each group do and which do 

 not intergrade ; lience all are here treated as species. This much, 

 however, may be said with considerable confidence: Canis latrans 

 inhabits the humid prairies and bordering woodlands of the 

 northern Mississippi Valley in Iowa and Minnesota, and follows 

 the northern edge of the plains westward to the base of the Rockj' 

 Mountains in the province of All:>erta. On the adjacent arid 

 plains from eastern Colorado to Montana and Assiniboia it is re- 

 placed by and probably intergrades with the veiy pale C. palli- 

 das. In cranial characters C. ■pallldus is closely related to the 

 form inhabiting the plains of the Columbia in eastern Oregon 

 and Washington, which appears to grade insensibly into C testes, 

 the Coyote of the Transition zone from the dry interior of south- 

 ern British Columbia, Washington, and Oregon southward over 

 the higher lands of the Great Basin, the Sierra Nevada, and the 

 Rocky Mountains to the plateau of northern Arizona, and thence 

 along the continental divide to the Mexican boundary. It is not 

 improbable, therefore, that the three members of the latrans group 

 intergrade, though no skins showing intergradation have been 

 seen. 



The three members of the frustror group, on the other hand, 

 are probably specifically as well as geographically distinct. Still, 

 the limits of their ranges are unknown. Canis frmtv or inhabits 

 the Gulf region of Texas from Nueces Bay northward and will 

 probabh^ be found throughout the Lower Sonoran area of Texas, 

 (Oklahoma, and Indian Territory. Its distant relative, C. cagottis, 

 is known from only the southern part of the tableland of Mexico, 

 but probably ranges northward along the west side of the table- 

 land. The third member of the series, C. peninsulae, is supposed 

 to be restricted to the peninsula of Lower California. 



The microdon group contains five very different forms. Of 

 these, C. microdon inhabits the arid tropical or ' Tamaulipan ' 

 fauna of northeastern Mexico and the Lower Rio Grande region 

 in Texas; C. vigilis the arid tropical coast region of Colima in 

 western Mexico; C. mearnsi the Lower Sonoran areas of north- 

 ern Sonora and southern Arizona ; C. estor the adjacent Lower 



