706 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
regarded. The measurements given beyond are taken from the skins, and 
seem to indicate a form nearly as large as the S. carolinensis from the South 
Atlantic and Gulf States; yet, on comparison of specimens, the feet of the 
Merida specimens prove to be much smaller, the head narrower and every 
way smaller, showing in reality a much smaller animal, not much exceeding 
in size S. hudsonius. The New Leon specimens, however, are fairly inter- 
mediate, lacking the fulvous tint of the sides seen in northern specimens, and 
in general color and character of the pelage considerably approach the Merida 
examples. 
De Saussure describes S. carolinensis as a Mexican species, and Tomes 
gives it as inhabiting Guatemala. De Saussure’s description indicates an 
animal not very different from the northern S. carolinensis, including the 
fulvescent sides and centrally rufous tail. The “cauda corpore vix brevior” 
and the size show the animal is not referable to S. colliai. This seems to 
indicate the extension southward of the habitat of S. carolinensis throughout 
Mexico to Yucatan and Guatemala, its range southward being thus coexten- 
sive with that of Lepus sylvaticus, L. palustris, and L. aquaticus. 
GENERAL REMARKS ON SCIURUS CAROLINENSIS AND ITS VARIETIES. 
DirFERENTIAL CHARACTERS.—Vars. /eucotis and carolinensis cannot of 
course be trenchantly defined On comparing specimens from New England 
with others from Florida, representing, of course, the extremes of variation, the 
differences between the two, both in color and size, are very striking; but, in 
passing southward from Massachusetts to Florida, this wide difference is found 
to be effected by gradual and imperceptible steps. In New England specimens, 
a large proportion are wholly without a central dorsal area of brown; in Penn- 
sylvania, Ohio, Illinois, and Iowa specimens, it is a pretty constant feature, 
varying greatly, however, in extent with different individuals. In Eastern 
Pennsylvania and Maryland specimens, this brownish dorsal area becomes 
more extended, but the sides of the body, and generally the rump, are still 
strongly washed with whitish. Carolina specimens, especially from the coast 
region, strongly approach the Florida ones. The few specimens before me 
from the Gulf States render it probable that the form existing there differs 
little from the extreme phase of carolinensis as developed in Florida. The 
variation in size is equally gradual, consisting of a decrease in size southward. 
The dividing line between the habitats of the two forms may perhaps be 
