MURIDA—SIGMODONTES—OCHETODON. 123 
= 
(In all this, however, there is nothing essentially different from Hesperomys.) 
The latter are very large and thin, and widely separated by a broad wedge- 
shaped basioccipital, their axes rapidly approximating from behind forward. 
In external form, there is little or no difference from Hesperomys to note. 
The hairiness of the tail and ears is much as in that genus, and more than in 
Mus. The tail averages about as long as the head and body—a little less in 
O. humilis, and a little more in O. longicauda and O. mexicanus. The fore feet 
are about half as long as the hind ones; both are rather scant-haired above, 
though the hairs reach to the end of the claws. The palms show the ordinary 
five tubercles. The soles are scantily hairy for about one-third their length, 
being for the rest granular-reticulate, with six very distinct tubercles: the 
first internal, midway between heel and base of inner toe; the second just in 
advance of this, but external; the third in advance of the second, but internal 
and at base of the inner toe; a fourth and fifth lie at bases of, respectively, 
the fifth and second toes; the sixth rests upon the conjoined bases of the third 
and fourth toes. 
We append the measurements of several skulls of Ochetodon, without 
distinction of species, since no specific characters rest upon peculiarities of 
the cranium. 
TABLE XXXIJI.— Measurements of five skulls of OCHETODON. 
& 2 Tip of under inci- 
SES 
z = i sors to— 
P| Ss g 
£ Locality. z = 2 3 S og |e? Species. 
i) 4a : 5 =] oa ad 6 = 2 
2 Ty Nes! 3 a 4 ea a |o s 
= iJ) = = ° wo 
g Se las witec is | aloes tes alee 
A Be |e Oi Een | aie tit Tee 
191 ) Saint Louis, Mo........| 0.76 | 0.40 | 0.12 | 0.29 | 0.14 | 0.47 | 0.37 | 0.46 | humilis. 
4Agg 48 ISONOLA\<25~5-%s/552--55- 0.82 | 0.43 | 0.13 | 0.30 | 0.15 | 0.50 | 0.40 | 0.49 | “megalotis.” 
2898 | Rocky Mountains ..--.. 0.78 | 0.40 | 0.11 | 0.28 | 0.13 | 0.48 | 0.38 | 0.45 | “montanus.” 
"334 =| Petaluma, Cal ......-... 0.69 | 0.38 | 0.11 | 0.26 | 0.12 | 0.42 | 0.31 | 0.40 | longicauda. 
sete |a----- Goss sssressecieses 0.70 | 0.40 | 0.12 | 0.27 | 0.13 | 0.47 | 0.35 | 0.46 |..---. do. 
* No. 2232 is, perhaps, not quite full-grown. 
OCHETODON HUMILIS, (Aud. & Bach.) Coues. 
Little Harvest Mouse. 
Mus humilis, Aub. & Bacn., Proc. Acad. Nat. Sci. Phila. i, 1841, 97; Journ. Acad. Nat. Sci. Phila. 1842, 
- viii, pt. ii, 300; Q. N. A. ii, 1851, 103, pl. Ixv (South Atlantic States). 
TTesperomys humilis, WAGNER, Wieg. Arch. 1843, pt. ii, 51 (after Aud. & Bach.). 
Reithrodon humilis, Barrp, M. N. A. 1857, 448 (South Carolina, Georgia, and ? Missouri). 
Ochetodor humilis, COUES, Proc. Acad. Nat. Sci. Phila. 1874, 185. 
Mus lecontii, Aup. & Bacn., Journ. Acad. Nat. Sci. Phila. viii, 1842, 207; Q. N. A. ili, 1654, 324 (tab. nulla), 
(South Carolina). 
