LEPORIDA—LEPUS SYLVATICUS. 329 
Specimens from the same locality differ in color mainly in the amount 
of black presented by the -dorsal surface, this depending upon the relative 
length of the black tips of the hairs. There is a slight variation also in 
respect to the intensity of the brown of the subterminal bar. The variation 
in color with the season is not very marked, consisting in winter specimens 
being somewhat grayer than summer specimens. Southern specimens are 
but little more strongly colored than northern ones, the rufous being of a 
rather stronger tint and the black more prevalent. Those from the States 
immediately west of the Mississippi River begin to be lighter than those from 
the Atlantic slope. Further westward, the paleness gradually increases till 
we reach the pale form of the arid plains. Specimens from northern locali- 
ties, both on the Atlantic slope and in the interior, are sometimes wholly 
without the brownish termination of the under-fur, or it is only faintly 
developed, and confined mainly to the sides. Here it is generally, however, 
quite strong, and is frequently quite appreciable on the middle of the dorsal 
region. The same variation in this respect is seen both in Massachusetts and 
western specimens; Iowa examples being not distinguishable in this respect 
from New England ones. To the southward, however, the brownish termi- 
nal band of the under-fur becomes more uniformly traceable, being generally 
present in specimens from about Washington, but much stronger in those 
from South Carolina and Florida, in which it generally forms a strong broad 
bar, though sometimes obsolete. 
The geographical variation in color is mainly as already noticed, namely, 
an increasing paleness from the Mississippi westward toward the Plains, 
where variety sy/vaticus passes by insensible steps into variety nuttadli 
(=artemisia auct.). The specimens from Eastern Nebraska and Eastern 
Dakota can, in general, hardly be referable to the one form rather than to the 
other. At the southward, the colors become slightly more intense, but the 
difference is by no means striking. The variation in size with locality is 
quite appreciable, as shown in Tables X XVII and XXVIII, the largest speci- 
mens being from the north. Washington specimens are somewhat larger than 
those from South Carolina and Florida,while those from Massachusetts are again 
rather larger than those from Washington; those from Wisconsin and Iowa are 
fully as large as New England specimens, and very much larger than Texas ones. 
Passing further south, however, we find, contrary to what would be antici- 
pated, that specimens from Southern Mexico are fully as large as those from 
