LEPORIDAS—ANALYSES OF SPECIES AND FAMILIES. 283 
Analysis of the species and varieties. 
I. Skull much arched above; breadth one half the length; postorbital pro- 
cesses distinct, not soldered with the skull; nasals of medium 
length, their length equal to about four-fifths of the width of the 
skull. 
A. Hind feet longer than the head. Size large. Peostorbital processes 
divergent, not in contact with the skull posteriorly. Pelage 
white in winter. ‘ 
a. Size large. Nasals about as wide in front as behind. 
1. Ears rather shorter than the head. Pelage dusky yellowish-gray 
in summer, pure white to the roots in winter. Tail short, black 
above in summer. Size very large .--.-- - timidus var. articus. 
2. Kars much longer than the head. Pelage pale yellowish-gray in 
summers; in winter, white at the surface and base and reddish 
in the middle. Tail long, white on both surfaces. Size 
Sie ere eM ure heme ok Pla kn Sule 2 campestris. 
b. Size medium. Nasals considerably narrower in front than behind. 
3. Ears about equal to the length of the head......---- americanus. 
3a. 
3b. 
3d. 
Pelage in summer pale cinnamon-brown; in winter, white at 
the surface and plumbeous at base, with a narrow middle band 
Gieened dish al no wale spews see ere et eee var. americanus. 
Pelage in summer cinnamon-brown; in winter, white at the 
surface and plumbeous at base, with a broad middle band of 
reddish-brown, which shows through the white of the surface, 
the white being often a mere surface-wash. Fully as large, or 
rather larger, than var. americanus....-..----- var. virginianus. 
Pelage redder in summer and whiter in winter than in the last, 
SNe SIZerRmNMIerA or. eels Sia teres var. Washingtoni. 
Size of the last, with the pelage more dusky and with generall 
’ pelag g 
little or no rufous in summer, and in winter nearly or wholl 
2) 
pure white to the base, the middle reddish band being com- 
monlytalmestiobsolete = asic. sisal ia iw Gee ke var. Bairdii. 
