272 RHITHRODONTOMYS. ACODON. 
Measurements. Total length, 180; tail vertebre, 113; hind foot, 
21. Skull: length from alveolus of incisors to posterior margin of 
palate, 9; palatal length, 5; length of nasals, 9; interorbital constric- 
tion, 3; length of molar series, 4. (ex Type.) 
270. dorsalis (Reithrodontomys!), Merr., Proc. Wash. Acad. Scien., 
Il, LOOM ps) 557. 
GRAY-BACKED Harvest Mouse. 
Type locality. Calel, Guatemala. 
Genl. Char. Size large; molars small; rostrum long. 
Color. Above grayish washed with buffy, and lined with black; 
dorsal area blackish; sides ochraceous: beneath buffy white; lips, chin, 
hands, and feet whitish; tail above dark, beneath whitish. 
Measurements. Total length,171; tail vertebra, 92; hind foot, 19. 
271. creper (Keithrodontomys!), Bangs, Bull. Mus. Comp. Zodl., 
Lol, 1902, Paar 
Dusky Harvest MOUusE. 
Type locality. Volcan de Chiriqui, Chiriqui, Panama. Altitude, 
11,000 feet. 
Genl. Char. Hind foot large; tail long; pelage long, silky. 
Color. Dorsal region bistre; sides raw umber; under parts dark 
cinnamon; hands and feet brownish; toes whitish; tail, basal two- 
thirds uniform dusky, terminal third white; ears dusky. 
Measurements. Total length, 215; tail vertebre, 130; hind foot, 
23; ear, 15. Skull: basal length, 21.4; occipito-nasal length, 25.4; 
mastoid width, 11.6; length of nasals, 8.8; length of palate, to palatal 
notch, 10; length of palatal slits, 4.8; upper molar series, 4.2; single 
half of mandible, 13.6. (Bangs, 1. c.) 
The next genus is peculiarly a South American one, where, with 
the exceptions mentioned below, all of its species are found. 
53. Acodon. 
l=; M=2= 16. 
I—I 3-3 y 
Akodon Meyen, Nova Acta Phys. Med. Acad. Caes. Leop. Carol., 
XVI, 1833, p. 599, tab. xLitl, fig. 1. Type Akodon boliviensis 
Meyen. 
Abrothrix (sic) Waterh., Proc. Zool. Soc., 1837, p. 21. 
Fur long, soft; tail short, hairy; ears hairy; thumb with a short 
nail. First molar with two indentations on both sides, the second 
molar one, and the third molar with one on outer side only. 
