21-2 RHITHRODONTOMYS. ACODON. 



Measurements. Total length, 180; tail vertebrae, 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., 



in, 1901, p. 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 Iength,i7i ; tail vertebrae, 92 ; hind foot, 19. 



271. creper (Reithrodontomys!), Bangs, Bull. Mus. Comp. Zool., 



xxxix, 1902, p. 39. 

 DUSKY HARVEST MOUSE. 



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 vertebrae, 130; hind foot, 

 23; ear, 15. Skull: basal length, 21.4; occipito-nasal length, 25.4; 

 mastoid width, n.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. Acodoii. 



Akodon Meyen, Nova Acta Phys. Med. Acad. Caes. Leop. Carol., 

 xvi, 1833, p. 599, tab. XLIII, fig. i. 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. 



