SCIURID—SCIURUS CAROLINENSIS AND VARIETIES. 707 
considered as the vicinity of the Potomac River on the Atlantic coast. 
Probably var. lewcotis occurs southward in the mountains to Georgia, while 
again, in the Mississippi Valley, the southern boundary of its habitat sweeps 
northward as far as Southern Illinois. Along the Atlantic coast, no melanistic 
phase of var. carolinensis has as yet been reported, but in Louisiana and 
northward along the Mississippi a melanistic phase has been said to occur, 
forming the S. fuliginosus of Bachman. 
GEOGRAPHICAL DISTRIBUTION —The present species ranges eastward 
along the Atlantic coast to New Brunswick, and is found thence westward 
over the southern half of Maine, most parts of Vermont, New Hampshire, 
and New York, most of the Saint Lawrence Valley, the southern portions of 
Canada, Michigan,* Wisconsin, Iowa, and up the Missouri, at least to the 
mouth of the Platte, and thence everywhere southward to the Gulf coast. 
It ranges westward to the eastern border of the Plains, from Nebraska to 
Texas, and apparently far into Mexico. Its northern limit of distribution 
coincides very nearly with the northern boundary of the Alleghanian fauna, 
and hence very nearly with the isotherm of 44° F. Variety deucotis may be 
considered as ranging southward over both the Allteghanian and Carolinian— 
faunze, or about to the isotherm of 56° F., where vars. /eucotis and carolinensis 
become not readily distinguishable. Var. carolinensis occupies the region 
thence southward, in the United States, to the Gulf coast, and also far into 
Mexico, and even apparently to Guatemala. 
In the United States, it has not been reported from any locality west of 
the eastern edge of the Plains or west of Texas. The specimens from New 
Leon, Mexico, are the most southern I have seen, and depart somewhat from 
any of the forms met with in the United States. The descriptions of S. 
carolinensis, from Mexican specimens, seem unquestionably referable to this 
species, and seem to indicate that the form met with in Central and Southern 
Mexico is not greatly different from the form occurring in the middle portions 
of the United States, though referred to as smaller and more fulvous. 
The form I have characterized above as var. yucatanensis is possibly 
specifically distinct, but, if so, has very close affinities with the New Leon 
type of S. carolinensis. The four specimens of this form in the collection 
are all from Merida, Yucatan. I have met with no description that is at all 
referable to this form, and can hence add nothing further respecting its range. 
* Richardson refers to the occurrence of the black form on the northern shores of Lakes Haron and 
Superior, and gives its range as extending northward to the fiftieth parallel—(laun. Bor.-Amer, vol. i, 
1829, p. 191.) 
