Allen.] 432 [February 17, 



46. Paler, rather smaller, with slightly larger ears, and 

 rather stouter lower jaw .... var. Nuttalli. 



4c. Color nearly as in var. sylvaticus ; rather longer ears, 

 more distinctly black- tipped . . var. Auduboni. 



5. Smaller than sylvaticus, with the postorbital process scarcely 



touching the skull posteriorly. Colors generally more 

 finely blended, and darker. Tail very short, almost ru- 

 dimentary , . . . Trowbridgei. 



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



Trowbridgei, with the colors and sparsely clothed feet of 

 palustris. Tail very short brasiliensis. 



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. Post- 

 orbital processes convergent, touching the cranium behind. 

 Pelage never white. Tail long, black above, this color ex- 

 tending forward on the rump. 



A. Lower jaw large, massive. 



7. Above pale yellowish gray, varied with black; below white, 



more or less tinged with fulvous callotis. 



B. Lower jaw disproportionably small, relatively smaller than 



that of any other American species of Lepus. 



8. Somewhat smaller than callotis, and more rufous above. 



calif ornicus. 



III. Postorbital process anchylosed with the skull. Hind feet short. 



Pelage never white. 



A. Width of the skull half of the length. 



9. Size medium. Tail long . . palustris. 



B. Width of the skull considerably less than half the length. 



10. Size large. Tail short aquaticus 



1. Lepus timidus var. articus. 



Lepus variabilis Pallas, Schreber, Gmelin and other early writers. 



Lepus timidus Fabricius, Faun. Groenl., 25, 1780. 



Lepus articus Leach, Ross's Voyage, II., App. 151, 1819. 



Lepus glacialis Leach, Ibid., 170. 



Lepus glacialis Sabine, Richardson, Baird, and subsequent writers 

 generally. 



Habitat. Arctic America, southward on the Atlantic coast to Lab- 

 rador and Newfoundland ; in the interior southward to Fort Churchill, 

 the northern shore of Great Slave Lake and the upper Youkon Valley. 



