214 MEGADONTOMYS. NYCTOMYS. 
blackish; hands and feet white; tail above dusky, almost black, 
beneath paler. 
Measurements. Total length, 350; tail vertebre, 188; hind foot, 
34. Skull: occipito-nasal length, 65; Hensel, 54; zygomatic width, 
32; 1nterorbital constriction, 9; length of nasals, 26; palatal length, 
33-5; length of upper tooth row, 11. 
190. nelsoni (Peromyscus), Merr., Proc. Biol. Soc. Wash., xu, 1898, 
p 126: 
NELSON’s FIELD Mouse. 
Type locality. Jico, State of Vera Cruz, Mexico. Altitude, 
6,000 feet. 
Geogr. Distr. State of Vera Cruz, Mexico; range unknown. 
Genl. Char. Similar to M. thomasi1, but darker. 
Color. Above and sides grayish brown, darkest on dorsal region; 
under parts white; tail dusky; hands white; hind feet dusky. 
Measurements. Total length, 302; tail vertebre, 172; hind foot, 
35° 
191. flavidus (Megadontomys), Bangs, Bull. Mus. Comp. Zodl., 
ReCIK, LOG2= p27 
BogueETtEe Mouse. 
Type locality. Boquete, Chiriqui, Panama. Altitude, 4,000 
eet 
Genl. Char. Braincase rounded and elevated; palatal slits very 
wide; audital bullze small; ears small. 
Color. Above brownish cinnamon, inclined to rusty on the rump; 
sides orange buff; black patch at base of whiskers; under parts white; 
pectoral collar buffy; hands and feet whitish; tail above dusky, 
beneath grayish; ears dusky inside, silvery outside. 
Measurements. Total length, 320-375; tail vertebra, 155-205; 
hind foot, 31-33; ear, 20-24. Skull: basal length, 35.4; occipito- 
nasal length, 40.2; zygomatic width, 19.6; mastoid width, 15; length 
of nasals, 17.8; width of nasals, 4.8: length of palatal slits, 7.4; width 
of palatal slits, 3.4; length of palate to palatal notch, 17; to end of 
pterygoid, 24.4; length of upper molar series, 5.6; length of single 
half mandible, 21.8. (Bangs, 1. c.) 
44. Nyectomys. Vesper Rats. 
PS Me ao, 
I—I 3-3 
Nyctomys Sauss., Rev. Mag. Zodél., 2me Sér., 1860, p. 106. Type 
Hesperomys sumichrasti Saussure. 
Myoxomys Tomes, Proc. Zool. Soc., 1861, p. 284, pl. XxXI. 
