392 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
List of specimens. 
Catalogue number. 
o 
6 
£ 
w> 
o 
O 
Sex and age. 
Locality. 
Whence and how 
obtained. 
| Original number. 
Nature of 
specimen. 
Measurements. 
o 
£ 
Nose to ear. 
Nose to occiput. 
Nose to tail. 
Tail to end of vert. 
| Tail to end of hairs 
Fore foot, length. 
Hind foot, length. 
| Fore claw,length. 
| Skull, length. 
j Skull, width. | 
Width of muzzle, j 
Width of incisors. | 
?475 
Tejon Valley, Cal 1 . 
Lt.R.S. Williamson 
2 
Mounted. 
?476 
.do. 
613 
1759 
Monterey, Cal. 
Lt.W. P.Trowbridge 
Skin .... 
1.60 
6.10 
3.08 
1.00 
1.50 
.33 
1.74 
.96 
.29 
366 
1280 i 
Mounted. 
1.80 
1.07 
.29 
.19 
367 
1281 
.... 
1.50 
.90 
.28 
.14 
2639 
A. S. Taylor. 
In ale.... 
.86 
1 52 
2.80 
.35 
2647 
... 
2.88 
1.00 
1.14 
2648 
• • • •. do... 
......do. .•••• ••••• 
..do..•••• 
.87 
1.50 
1.70 
5.70 
2.27 
.80 
1.00 
938 
William Hutton.... 
Skull. .. 
1.58 
.89 
.30 
.18 
2649 
San Jose, Cal. 
A. .T. Grayson. 
In ale.... 
.90 
1.52 
2.05 
5.85 
2.70 
1.13 
1.20 
.36 
2650 
.85 
1.50 
1.90 
5.46 
2.50 
.95 
1.04 
.30 
604 
p. T). Cntts.. T . 
Skin_ 
1.84 
7.50 
2.10 
1.00 
1.16 
.42 
1757 
1.75 
6.75 
2.50 
2.67 
.90 
1.10 
.37 
.32 
.20 
605 
6.00 
2.15 
.97 
.31 
2646 
.... 
.do.. .. 
Lt.W. P.Trowbridge 
.85 
1.35 
1.80 
5,41 
2.30 
.90 
1.05 
.26 
2640 
Petaluma, Cal. 
E. Samuels. 
.85 
1.36 
1.55 
4.60 
2.50 
1.20 
.30 
2641 
.45 
1.05 
1.23 
3.90 
1.20 
.70 
.80 
.20 
1 ° 
* Collected by Dr. Heermann. 
THOMOMYS LATICEPS, Baird. 
Broad-headed Gopher. 
Thomomys laticeps, Baird, Pr. A. N. Sc. Phil. VII, April, 1855, 335. (Humboldt Bay.) 
Sp. Ch.— pheelc pouches moderate, well haired. Tail nearly one-half the body, thick at base. Skull very broad and 
muzzle short; the upper incisors convex, the groove quite distinct. Feet very large and broad. Claws of fore foot or 
hand small, slender, 4 lines long above; below, about two-sevenths the length of the whole hand, its digit about two- 
eighths. Claw of thumb extending over nearly three-sixths the hand. 
Color. —Above, yellow reddish brown ; the dorsal region with the hairs largely and sharply tipped with blackish; sides 
nearly uniform ; beneath, tinged with reddish. Pouches dull white, the dusky of the surrounding region dipping into 
them. Tail grayish white, dusky above. 
This species, with one from the upper Missouri, is eminently characterized amohg all those 
with smooth upper incisors hy the very hroad and powerful feet and larger hands. The ear 
flap is short though distinct; the whiskers short and of a grayish color. The fur is soft, silky, 
and moderately long. The tail is much developed, very thick at the base, and almost half the 
length of the body, well coated with hair. The pouches are not very large, densely furred 
inside next the head, more sparsely elsewhere. 
The fore feet are large, especially the palms; the first finger or thumb is short, though 
inserted quite far forwards its claw does not quite reach to the middle of the hand, (from wrist 
to point of claw.) The claws generally are rather small, much curved, and quite slender ; the 
third projects, on its lower edge, to a distance which is contained about three and a half times 
in the entire hand, or -f-ths ; its phalanges only about half the length of the palm proper. 
The second finger and claw are considerably longer than the fourth ; the point of -the fifth claw 
extending more than half the total length of the hand ; the first claw extending as far as the 
