LEPORIDAS—LEPUS SYLVATICUS VAR. NUTTALLI. 331 
are scarcely smaller than those from Iowa or the Eastern States, while the 
proportions seem to be absolutely the same. 
This form was formerly supposed to be much smaller than L. sylwvaticus, 
but the large number of specimens before me indicates but a slight average 
difference in size, var. nut/alli being rather the smaller, with a very decided 
decrease in size to the southward. Specimens from the northward have a 
fuller and softer pelage and more heavily-clothed ears and feet than var. 
sylvaticus anywhere presents. In those from along the eastern edge of the 
plains, the tints are brighter than in those from further westward ; specimens 
from along the Missouri, from about Fort Leavenworth to above Fort Randall, 
being so nearly intermediate between the typical nuttalli and sylvaticus that 
the majority of them may be as well referred to the one furm as to the other, 
while there may occur occasionally typical examples of each. The lightest 
specimens appear to be those from Western Wyoming, Colorado, Nevada, and 
Utah; Arizona specimens passing gradually into variety arizona. Winter 
specimens are rather lighter than summer ones. In some of the former, the 
subterminal zone of the hairs presents but a faint trace of yellowish, while the 
sides and hinder part of the back are of a delicate gray, from the intimate 
biending of the black and white hairs. Through the excessive paleness or 
almost total obsolescence of the yellowish-brown tint so conspicuous in var. 
sylvaticus, the black tips of the hairs are more conspicuous, standing out in 
stronger relief against the nearly white ground-color, and thus sometimes 
give the effect of a greater amount of blackness. 
The average length of the body in a series of nineteen specimens from 
various localities is 13.75 inches, with the extremes ranging from 12.00 to 
16.00; of hind foot, 3.41 inches, with the extremes ranging from 3.00 to 4.25. 
The average length of fifteen specimens from the Atlantic slope is 15.35 ; 
of twenty specimens from the vicinity of the Missouri River (from various 
localities between Fort Randall and Fort Leavenworth), is 15.50. Variety 
nuttalli hence averages about one and a half inches shorter than var. sy/vati- 
cus, or about 12 per cent. smaller. The measurements of the skulls indicate 
about the same proportionate difference in size. 
There are in the collection a considerable number of specimens collected 
in the vicinity of Brownsville and Matamoras, near the mouth of the Rio 
Grande. These include Baird’s types of his L. “bachmani” (= bachmani 
Waterhouse), which I at first referred to variety nu/talli, but now believe to 
