MURID2E— SIGMODONTES— OCOETODON. 



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 Heqwomys 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. 



* No. 2282 is, perhaps, not quite lull-grown. 



OCHETODON HUMILIS, (And. & Bach.) Coues. 



Little Harvest Mouse. 



Hits humilis, Aud. & Bach., Proc. Acad. Nat. Sci. Phila. i, 1841, 97 ; Journ. Acad. Nat. Sci. Phila. 1842, 

 viii, pt. ii, 300 ; Q. N. A. ii, 1851, 103, pi. Ixv (South Atlantic States). 



Uespcromys humilis. Wagner, Wieg. Arch. 1843, pt. ii, 51 (after Aud. & Bach.). 



Reithrodon humilis, Baird, M. N. A. 1857, 448 (South Carolina, Georgia, and ? Missouri). 



Ochelodop humilis, Coues, Proc. Acad. Nat. Sci. Phila. 1874, 185. 



M i/s lecontii, Ann. & Bach., Journ. Acad. Nat. Sci. Phila. viii, 1842, 307 ; Q. N. A. iii, 1854, 324 (<«&. nulla), 

 (South Carolina). 



