SCIURIDA—SCIURUS—SYNOPSIS OF SPECIES. 671 
IJ. Tail-vertebre about four-fifths (five-sixths to three-fourths) the length of the head and hedy; ‘tail, 
with the hairs, rather longer than the body (in most of the species one-twelfth longer), 
generally fulland bushy. Premolars usually 7; ina few species }. Size large or medium: 
A. Premolars 7: 
2. Above whitish-gray, varied (except in one subspecies) with fulvous; beneath white; middle 
of back more or less brownish ; an indistinct fulvous lateral line; ears never conspicu- 
ously tufted. Hab.—Southern parts of Canada, the United States east of the Plains, 
and southward to Southern Mexico and Guatemala --.......... .....S. CAROLINENSIS. 
a. Above whitish-gray, with generally a small, narrow, brownish area along the middle of 
the back; length from nose to tail 10.00 inches or more; runs frequently into melanistic 
phases, which are sometimes wholly black. Hab.—United States and Southern Canada 
southward to the Louisianian fauna .-..-.....--. tceease accett ceo tena var. leucotis. 
b. Smaller; generally less than 10.00 inches in length; greater part of dorsal surface 
brownish, sides only whitish-gray; rarely runs into melanistic phases. Hab.—South 
Atlantic and Galf States and southward .........-....---..----.----- var. carolinensis. 
e. Still smaller; plain dull-gray, unvaried with fulvous; middle of the back darker. 
HGP ——YUCAPAM satel ale ea a emit ama sls) =i SAD BOCES ER Mato acnone mareserae var. yucatanensis. 
3. Above dark bluish-gray; a dorsal band of bright chestnut; a distinct black lateral line; no 
fulvous suffusion ; below white; ears very large, each with a conspicuous tuft or pencil 
of long hairs, as in S. vulgaris ; runs into melanistic phases. Hab.—Rocky Mountains 
of Colorado; Southward:into Arizona..22.. 22222 o-cc-~ occ cane esicee oe sauce S. ABERTI. 
4. Above dark brown, varied with yellowish-gray, or black, varied with fulvous; beneath 
deep brownish-red; color very variable. Hab.—Southern Mexico und Central 
JN TIE E Baca sO SCH OLD OSE CROC CERO UED eee cee Nocera ee cree cas S. BOOTHIE. 
5. Above gray, varying from whitish to dark iron-gray, generally with a large patch of yellow- 
ish-rusty on the nape and lower part of the back; beneath pure white, yellowish-white, 
or deep golden-yellow ; pelage generally ringed with bright fulvous beneath the surface ; 
tail rather narrow; very variable in coloration. Hab.—Southern Mexico..S. LEUCOPs. 
6. Above dark gray, varying from whitish-gray to dusky iron-gray; beneath deep reddish- 
orange, invading irregularly the gray of the sides, the red wash of the sides sometimes 
nearly meeting on the dorsal line at the shoulders; pelage soft and full; tail bushy. 
Hab.—Southern Mexico and Guatemala ......-..--.-----------------S. AUREOGASTER. 
7. Above dark olivaceous-brown, minutely varied with yellowish or rufous; beneath gray 
varying to rufous; tail rather narrow; Jength about 9.75; tail with the bairs abont 
the same or a little less; size and general appearance of S. @stuans var. rufoniger, but 
with two upper premolars instead of one; smaller than either of the preceding, with 
narrower and shorter tail. Hab.—Southern Mexico, Central America, and northern 
portions of South America...--......----------+-----+ --+--------- S. TEPHROGASTER. 
B. Premolars }: 
8. Color above generally some shade of gray, but extremely variable; rusty and melanistic 
phases very prevalent; size large; tail broad and bushy. Runs into three subspecies. 
Hab.—Eastern United States westward to the Plains......-.---..------------ S. NIGER. 
a. Length abont 13.00 inches; color variable, but with the nose and cars white, contrasting 
with the color of the rest of the dorsal surface; generally whitish-gray above, running 
into rufous; below generally fulvous or rnfous; dusky phases frequent. Hab.—Sonth 
Mil axiiiC An CGT SCALES AoE e Seares oe eisa a eae cc cela ea ane esaeac neicteels nem aintet el var. niger. 
b. Smaller; length generally less than 13.00 inches; similar in color to var. niger, but with 
the nose and ears not white, in contrast with the rest of the dorsal surface. Hab.— 
Northern Atlantic States from Virginia to New England......-..--..----- var, cinereus. 
c. Size of the lust; less variable in co'or; above dusky-gray, strongly suffused with rufous ; 
ears, feet, and ventral surface fulvous, varying to rufous ; occasionally dusky or black 
beneath. Hab.— Whole of the Mississippi Basin, extending westward to the Plains and 
northward into Dakota..---. .-.--. 2.0 cocees won cen eee enna ee nnee «WAT. Luedlovicianus. 
