MAMMALS OB^ THK MEXICAN BOUNDARY. 851 



when compared witli tlie beaver of Arizona and Sonora . There being 

 at present no forest connection between the habitats of Castor fiber 

 and C. canadensis in their respective geographic ranges, and conse- 

 quently no continuity of habitat, there can be no question as to their 

 specific distnictness. The skuh of 0. canadensis frondator (ficr 57) 

 differs from that of typical C. canadensis in being' much larc.er"with 

 more spreading zygomata. ^ 



Pig. 07.-CAST..R canadensis rnoNDATOR. (Type, Cat. No. 35883, U.S.N.M.) „, 1„.ksv, vikw /> 

 Ventral VIEW: c, Lateral View. ' ' ' ■ ' 



Variations.-hxilxe year 18S5 I purchased from a professional trap- 

 per 17 beaver skms, taken on the Verde River during the winter (,f 

 .1884-85. Theso skins wore dried in oval shapes on fooped sticks in 



