No. 392.] AMERICAN ARBOREAL SQUIRRELS. 639 
this paper four species and 13 additional subspecies were recog- 
nized, four of the latter being described as new. 
The last complete revision of the arboreal squirrels of North 
America north of Mexico was made in 1877,! when six species 
and seven additional subspecies were recognized. Since that 
date not only has a large number of new forms been added and 
important changes in nomenclature been made, but the point 
of view has become radically changed through the accumulation 
of a vast amount of additional and far better material than was 
available twenty years ago. In consequence of this it may 
be a convenience to those interested in our mammals to give 
in this connection a list of the 10 species and 25 additional 
subspecies of arboreal squirrels, now recognized by experts as 
found north of Mexico, with a brief statement of their ranges. 
Arboreal Squirrels Found in North America North of Mexico. 
SUBGENUS HESPEROSCIURUS NELSON. 
a 
Sciurus griseus Ord. California gray squirrel. Southwestern Wash- 
ington, western Oregon, and California. 
. Sciurus griseus nigripes (Bryant). Coast region of California south 
of San Francisco. 
i 
a 
16. Sciurus griseus anthonyi Mearns. Anthony’s gray squirrel. Interior 
of southern and lower California. 
SUBGENUS NEOSCIURUS TROUESS. 
2. Sciurus carolinensis Gmel. Southern gray squirrel. Eastern United 
States, from southern New York to northern Florida. 
2a. Sciurus carolinensis leucotis (Gapper). Northern gray squirrel. 
Northern Alleghanies, and northward to New Brunswick and 
southern Canada. 
26. Sciurus carolinensis hypopheus Merriam. Merriam’s gray squirrel. 
Minnesota and Wisconsin. 
2¢ 
Sciurus carolinensis fuliginosus (Bachman). Bayou gray squirrel. 
Coast region of Louisiana. 
2d. Sciurus carolinensis extimus Bangs. Southern half of Florida. 
SUBGENUS OTOosCcIURUS NELSON. 
3. Sciurus aberti Woodhouse. Abert’s squirrel. Mountains of Colorado, 
New Mexico, and Arizona. 
3a. Sciurus aberti concolor True. Northeastern Colorado. 
1 Allen, J. A. Monog. N. Am. Roden. (1877), pp- 633-778, passim. 
