XVI. COMPARISON OP EXTERNAL CHARACTERS OF Castor subauratus subauratus TAYLOR, FROM THE SAN JOAQUIN VALLEY CALIFORNIA WITH Castor 

 canadenvs pacific*, RHOADS, FROM LAKE KEECHELUS, WASHINGTON, AND WITH Castor canadensis frondator MEARNS 



FROM THE SAN PEDRO RIVER, MEXICO 



Castor suoauratus subauratus Castor canadensis paciflcus Castor canadensis frondator 



Points of Comparison (ten examples) (one example) (one example) 



General coloration Medium pale. Similar to subauratus, perhaps slightly Paler than in subauratus. 



paler than the average of the series. 



Dorsal overhair Cinnamon to light pinkish cinnamon; pos- Varying from cinnamon in the middle of Varying about cinnamon. 



sessing luster in strong light which is the back to lighter tints both posteriorly 



not so evident in other forms. and anteriorly, attaining a pinkish buff 



color above the tail and on the cheeks. 



Dorsal underfur Varying about dark purple-drab, dark Varying about brownish drab. Pale tints of the drab series, near cinna- 



vinaceous-drab, dusky brown, and dark mon-drab, light cinnamon-drab and lighl 



grayish brown. drab. 



Whiskers Varying from cream color and light buff Near deep brownish drab. Clay color and darker. 



to somewhat darker shades of the series. 



Forefeet Varying from vinaceous-buff, avellaneous, Near avellaneous or wood brown. Mixture of colors which in combination ap- 



and wood brown, to fawn color, deep proach clay color and hazel, 



olive-buff, and even warm buff. 



Hind feet Varying about benzo brown; no. 12654 near Close to benzo brown. Mixture of colors close to clay color and 



chestnut. chestnut-brown; the chestnut-brown more 



in evidence than the clay color, making 

 foot appear darker. 



Ventral overhair Varying about benzo brown; approaching Cinnamon-drab to light cinnamon-drab. Close to cinnamon-buff. 



light buff about fore limbs. Luster in 

 evidence. 

 Ventral underfur Varying about pallid vinaceous-drab. Drab-gray to pale ecru-drab. Decidedly lighter than in subauratus; ap- 



proaching pale ecru-drab and pale drab- 

 gray. 



Base of tail above Varying about cinnamon; range of varia- Varying from the fringe of cinnamon-drab A fringe of hairs at immediate base of tai7 



tion approximately between pinkish cin- or benzo brown hairs to cinnamon-buff colored near hazel and chestnut-brown, 



namon and cinnamon-rufous. or even to pinkish buff ten cm. anteriorly 



of base of scaled portion of tail. 

 Rase of tail beneath Rather narrow zone of hairs varying be- Cinnamon-buff to pinkish buff, with a wash Broad area at immediate base of tail and 



tween pinkish cinnamon and chestnut; in of cinnamon-drab close to base of scaled extending somewhat anteriorly from it 



some specimens there seems to be little portion of tail. colored near hazel and chestnut-brown. 



difference in coloration between rest of 



underparts and base of tail. .. _,. .. , 



Tail Proportionally broader than in paciflcus, Averages narrower proportionally than in Averages broader proportionally than in 



narrower than in frondator. either of the other species. either subauratus or paaficus. 



