706 MONOGRAPHS OF NORTH AMERICAN KODENTIA. 



regarded. Tin' measurements given beyond are taken from the skins, and 

 seem to indicate a form nearly as large as the S. carolinensis from I lie South 

 Atlantic and Gulf States; yet, on comparison of specimens, the feet of the 

 Merida specimens prove to he 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. carolineiisis throughout 

 Mexico to Yucatan and Guatemala, its range southward being thus coexten- 

 sive with that of Lepus sylvaticus, L. ]mlustris, and L. aquaticus. 



GENERAL REMARKS ON SCIURUS CAROLINENSIS AND ITS VARIETIES. 



Differential characters. — Vars. leucotis and carolinensis cannot of 

 course be trenchantly defined On comparing specimens from New England 

 with olhers 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 



