478 U. S. P. R. R. EXP. ANUD SURVEYS—ZOOLOGY—GENERAL REPORT. 
List of specimens. 
| Measurements. 
g | 2 | g/£l3|s 
= S = S\/e/Sle]e 
5 6 5 Locality. When col- | Whence and how ob- Nature of B).is/s | z = g 
a gs 5 lected. tained. specimen. S g 3 FI zis , a2 s 
= a b=] rey eee fect eae = Se |e 2 e|\e 
a 7 =] \elelelelcolo|s sie 
Zg/Ele gle\2|elalsl|PlEIFIS 
s 5 Ep ° o o o s i] = co o o 
SM FOU ae | 2|4|4|4|/8)/&|4iaja le 
989 Racine, Wisconsin....... eecelocecle seceleeeeleeeeleeerlevenleeerlenee 
25531 .50} .83)1,04]3.00)2.17/2.33] .42) .70] .97) .44 
REBT |eescenlasncns|essancGO, cneusiacissioees cess 48) .80)1.00)3.18)2,22),...| .34) .74)....| .40 
Pv acbe leases! Fadssa) Msadacd Msaaapacstopssoecos 45) .85).. 30) .70)....| .50 
72669 ene cceeccceences 44) .85).. 30) .68). 43 
650 field, Ill....«+| April 18,1855 RB. Kennicolt ....ceep4 || SEil«.00s000|\s000] 0-000] os00)| sane] esanl cmos] Uene ieee ae 
739 Be Ree ery Ser bard > Se) o-- 
2756 2.70/1.70)....| .35) .68)....| .44 
2757 3.03}1.92/2.02) .30) .70)....| .48 
2758 2,95/2.02)....| .30) .68) AS 
2759 3.20/2.25/2.33} .35) .70}....| .48 
2760 2-94). 33)2.45 32) .71 48 
2761 2.85)/2,20/2.37| .30) .68 46 
. 2763 3.43/2,55/2.72| .36) .70)....] .55 
2764 2.92/2.05)....| .30} .65)....| .50 
2765 3.20/2,192.35| .35) .75)....| .48 
2766 8/2.90 2.08)2.26 +30) .65)....| .48 
2771 3.322. 182.32) 232] «10 eecclenee 
782 wleccalsccclecesleccelsceclecenleces 
645? 8.00}1.64)2.00).... Bed ce Meee 
646° 2.93]1.93/2.00]....]..02|eeesleoee 
701° abl Goh eee Pe | Poe 
1 Measured before skinning, Fore arm, .55; from elbow to end of claws, .90; longest fore and hind claws, each, .06; from knee joint to end of 
claws, 1.42; tibia, .83; mamme 4 abdominal, two pectoral. 
2 Measured before skinning. 
HESPEROMYS CALIFORNICUS. 
Mus californicus, Gampet, Pr. A. N. Sc. Phila. IV, August, 1848, 78, (Monterey.) 
Sp. Cu.—Very large. Size of third grown rat. Lars very long, angular. ‘Tail rather longer than body. Color above, 
sooty brown, passing on the sides to fulvous. Under parts white, tinged with fulvous and ashy. Feet white. Tail 
brown, a littler darker on the dorsal line. Soles entirely naked. 
This is one of the largest, if not the largest, of the North American Hesperomys, with the 
exception of the H. palustris of Georgia. The ears are enormously large, in this respect cer- 
tainly exceeding any other species; they are considerably higher than broad, and, instead of 
being rounded uniformly at the tips, are cut at nearly a right angle with the corners rounded. 
They are uniformely coated with short white hairs, which do not form a fringe, as on Neotoma. 
The hind feet have the soles naked from the heel. The tail is considerably longer than the 
body, very thick and stout, as in the rats. The fur is very soft and full. 
The middle of the back of this species is a mixed black and grayish plumbeous, the former 
greatly predominating ; towards the sides there is less black, and light brownish yellow makes 
its appearance, forming quite a conspicuous stripe on the lower part of the sides, less distinct 
on the cheeks. The dusky extends to the wrist and heel, though the upper surfaces of the feet 
are entirely white. The under parts are dull whitish, strongly tinged in places with fulvous, 
