U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
doubt whatever that, with very few exceptions, the many species described by Audubon and 
Bachman as from California are really from Southern Mexico, adjacent, perhaps, to southern 
California, and have no right to a place in a fauna of North America, certainly not of the 
United States. 
Detailed measurements of a specimen in alcohol . 
Current 
Sex. 
Locality. 
Tip of nose to— 
Tail to end of— 
Length of— 
number. 
Eye. 
Ear. 
Occip. 
Tail. 
Vert. 
Hairs. 
Fore ft. 
Hind ft. 
2413 
o 
Petaluma, Cal_ 
1.35 
2. 45 
2.8 
11. 25 
11.5 
14. 75 
2. 
3.1 
List of specimens . 
j Catalogue number. 
£ 
o 
Sex and age. 
Locality. 
When col¬ 
lected. 
Whence obtained. 
Original number. 
Nature of spe¬ 
cimen. 
Mce 
Head 
and 
isurements. 
Tail. 
Collected by— 
Vert. 
Hairs. 
1002 
O 
Fort Dalles, O. T. 
Jan. 17,1855. 
Dr. Geo. Suckley. 
36 
Skin. 
12.50 
15.50 
1003 | 
2010 
V 
A 
Jan.15,1855. 
.do. 
37 
..do. 
11.25 
10.60 
14.00 
1004 
2011 
o 
o 
Jan. 15,3855. 
. . . do. 
38 
, .do. 
11.50 
11.00 
14.25 
1175 
V 
Fort Jones, Cal. t . 
1855. 
Lt. R. S. Williamson.... 
Dr. J. S. Newberry. 
1173 
2117 
Stockton, Cal_ T T , tTT 
do. 
do.. . .. 
2413 
o 
Petaluma, Cal. 
E. Samuels.... . 
214 
Entire in alch’l. 
609 
. 
San Francisco, Cal. 
R. D. Cuffs. 
Skin. 
; 2463 
Lt. W. P. Trowbridge 
1174 
Lt. R. S. Williamson... 
Dr. J. S. Newberry. 
480 
1604 
Fort Tejon, Cal. 
Mounted .. 
Dr. A. L. Heermann. 
2462 
San Diego, Cal 
Dr. Thomas H. Webb 
Skin. 
SCIURUS CASTANONOTUS, Baird. 
Chestnut Backed Squirrel. 
Sciurus caslanolus, Baibd, Pr. A. N. Sc. Phila. VII, April, 1855, 332. (Typographical error for castanonotus.) 
Body about 11 inches. Tail, with the hairs, but little longer. Hind feet 2.60 inches, skull, 2.40. 
Size about that of .S', cinereus. Five permanent molars in the upper jaw. Tail about equal in length to the body, not 
bushy. Ears with rather short hairs, not tufted. Soles naked in winter. Back deep chestnut brown ; rest of upper parts 
mixed ash, gray, and lead color. Eyelids, upper surfaces of feet, and whole under parts white. Ears and sides of head 
ash gray. The sides, tip, and under parts of tail, pure white ; above (within the margin) mixed black and white. 
A detailed description of this squirrel will be found in the report of the Zoology of the United States and Mexican 
Boundary Survey. 
This species hears a very close resemblance to S. aberti and may prove to he the same, 
although there are abundant differences. The most striking characteristic is the absence of the 
beautiful ear tufts of S. aberti. Some of our squirrels which have smooth ears in summer are tufted 
in winter, but as the Coppermines specimens were caught in winter, it is not likely that they are 
ever tufted. The tufts, too, of S. aberti are long hairs growing from the very margins of the 
ears and projecting an inch beyond. The convexity of the ear and a woolly space at their 
