452 U. Ss. P. R. R. EXP. AND SURVEYS—ZOOLOGY—GENERAL REPORT. 
List of specimens. 
4 Measurements. 
3 
s a c = z = 1 
2|%s j 5 3 a fe = ec 
=| é c Locality. Whence and how obtained. = Nature of 7 4 a 2 e 5 5 5 a 
= z2|\¢ 5 | specimen.| & = S 3 = zs eet Pees = 
© ew | 3 5 o ® ) = 5 =) s So 5 
eel seat |igct 3 8 |S lo2 \) 2) .e lhe seein 
> rs S 4 © © © © = = o so = 
m = * a) Do 77 QD a = = — & = 
& |S ja 5 zlelel2/esel/e |e |)haae 
1418" | 2282 | Q | Petaluma, Cal......... 75 | 2.08 | 2.25 | 2.33 |..sesclecveee .70 
1583: | 2411 |.... 83 | 1.83 | 2.25 | 2.33 |c.cecclscccns|ensee . 
1419: | 2283 |,... 83 | 2.25 | 2.42 | 2.60 |...... cecleccecs 
2581 |...... see 90 | 2.15 | 2.50 |...... 25)| nolleseees 
Q5B2 | receas sales 86 | 2.15 | 2.45 |...... 30 G5 |oecsce 
POSS Hewes. @jecue 95 | 2.10 | 2.80 |...... 32 6B |..cee . 
Q5B4 [eccces S26 90 | 2.10 | 2.40 |...... 26 60 | cseee 
B585 | renee Siri 90 | 2.13 | 3.15 |...... 30 70 | .wcnse 
2585. |escses ais 84 | 2.00 | 2.35 |...... 25 63 | .cceee 
2587 | revcee S250 90 | 2.30 | 2.65 |....0.] 30 nt Peers . 
2588 |..cs0s eevee 90 2,00 | 2.60 30 63 | ...00 . 
DOOD) lwerene eee 90 | 2.40 | 2.88 |... 31 165 |ecoes . 
2590 |...... as 90 2.10 | 2.70 |... 30/|| 265) scons. 
DOOR: sl auete ote 89 2.20 | 2.65 |...00. 30 60). sess 
27082 |...... epee 88 Re ec sconce 26 63) heen . 
* Measured before skinning. 2 Collected by W. Stimpson. 
There is a small mouse, described by Audubon and Bachman, under the name of Mus caroli- 
nensis, which appears different from Reithrodon humilis, but in the grooved incisors seems to 
belong to the same genus. They mention it as existing very sparingly in the maritime districts 
of South Carolina, and found usually in low grounds, partially inundated. The description is 
as follows: 
REITHRODON CAROLINENSIS. 
Mus carolinensis, Aup. & Bacu. J. A. N. Sc. Phil. VIII, m1, 1842, 306.—Is. N. Am. Quad. III, 1854, 332. 
Hesperomys carolinensis, Wacner, Wiegm. Archiv, 1843, 1, 51. 
Sp. Cu..—Upper fore teeth slightly grooved ; tail, half an inch longer than the body ; ears long; color, light plumbeous; 
under parts and hind feet scarely lighter. 
Point cf nose, lips, chin, fore feet, and nails, white ; whiskers, dark brown. A narrow fawn- 
colored ring round the eye. Ears, legs, and tail, light ashy brown. Fur on the back and sides 
uniform light plumbeous ; the under surface scarcely a shade lighter. 
Inches. Lines. 
Length (of head and bod ywoan ae sac soe aoe eee 2 4 
tell SG esse ee ea eee eee 2 9 
Height ‘ofeats. 225-2. eee ee aaa eee ee ee en 4 
hength of ‘tarsus 2 -fadoe-8) oe oka se geneae doce ees ces sant wa anne oe 63 
The grooved incisors distinguish this species from the common mouse, and the Hesperomys 
leucopus; from the other North American Reithrodons the dark color of the belly and hind feet 
constitute a decided characteristic. 
