SCIUMD2E— SCIURUS— SYNOPSIS OF SPECIES. 671 



II. Tail-vertebra* about four- fifths (live-sixths to three-fourths) the length of the head ami body; tail, 

 with the hairs, rather longer than the body (in most of the species one-twelfth longer), 

 generally full and bushy. Premolars usually § ; in a few species \. Size large or medium : 



A. Premolars j : 



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, tbe United States east of the Plains, 



and southward to Southern Mexico and Guatemala S. cabolinensis. 



o. Above whitish-gray, with generally a small, narrow, browuish area along the middle of 

 the back; length from nose to tail 10.00 inches or more ; runs frequently into melanisl io 

 phases, which are sometimes wholly black. Hab. — United States and Southern Canada 

 southward to the Louisiauiau fauna 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 aud southward var. earolinensis. 



c. Still smaller; plain dull-gray, unvaried with fulvous; middle of the back darker. 



Hab. — Yucatan 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 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 and Central 

 America S. boothi/e. 



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. i.eucops. 

 (i. 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 aud Guatemala S. aureogastek. 



7. Above dark olivaceous-brown, minutely varied with yellowish or rufous; beneath gray- 



varying to rufous ; tail rather narrow; length about 9.75; tail with the hairs about 

 the same or a little less ; size aud general appearance of <S. amtuans var. rufoniger, but 

 with two upper premolars instead of one; smaller thau either of the preceding, with 

 narrower and shorter tail. Hab. — Southern Mexico, Central America, and northern 

 portions of South America. S. teI'HKOGAster. 



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 about 13.00 inches; color variable, hut with the nose and ears white, contrasting 



with the color of the rest of the dorsal surface; generally whitish-gray above, runuing 

 into rufous; below generally fulvous or rufous; dusky phases frequent. Hab. — South 

 Atlantic and Gulf States var. niger. 



b. Smaller; length generally less than 13.00 iuches; similar in color to var. niger, hut 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 last; 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 var. huloririaiiu*. 



