284 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



15. Hind feel not longer than the bead. Size small. Postorbital processes 

 convergent, frequently (in old specimens) in contact with the 

 skull posteriorly, but only rarely anchylosed with it. Pelage 

 never white. 



4. Gray above, varied with black, and more or less tinged with light 



yellowish-brown ; under parts white sylvaticus. 



4a. Above yellowish-brown, with a tinge of reddish, var. sylvaticus. 

 4b. Paler, rather smaller, with slightly larger ears, and rather stouter 



lower jaw var. Nuttulli. 



Ac. Color nearly as in var. sylvaticus; ears rather longer and more 



distinctly black-tipped var. Audubon/. 



4.d. Like var. Nuttalli, but paler, and with considerably longer 



ears var. arizonce. 



5. Smaller than sylvaticus, with the postorbital process scarcely touching 



the skull posteriorly. Colors generally more finely blended, and 

 darker. Tail very short, almost rudimentary Trowbridgei. 



6. Above gray, varied with black and pale yellow. Size of Trow- 



bridgei, with the colors and sparsely-clothed feet of palustris. 

 Tail very short, yellowish-brown below brasiliensis. 



7. Size of sylvaticus, with the coloration much as in brasiliensis. Tail 



white below. Feet sparsely haired, as in L. palustris. . Graysoni. 

 II. Skull less convex above; breadth considerably less than half the length; 

 length of nasals more than four-fifths the width of the skull. 

 Ears and hind feet longer than the head. Postorbital processes 

 convergent, touching the cranium behind. Pelage never white. 

 Tail long, black above, this color extending forward on the 

 rump. 

 A. Lower jaw large, massive. 



8. Above pale yellowish-gray, varied with black ; below white, more 



or less tinged with fulvous callotis. 



8a. Pale yellowish-gray above, varied with black; below white, 



tinged with fulvous var. callotis. 



8b. More suffused with pale rufous throughout, with rather longer 



cars var. texensis. 



13. Lower jaw disproportionably small, relatively smaller than that of any 



other American species of Lepus. 



9. Somewhat smaller than callotis, and more rufous above, .californicus. 



