NYCTOMYS. TYLOMYS. 217 
Measurements. Total length, 250-260; tail vertebre, 120-125; 
hind foot, 25; ear, 17. Skull: basal length, 28; occipito-nasal length, 
32.4; zygomatic width, 18; mastoid width, 13; interorbital width, 
11; length of nasals, 10.6; width of nasals, 3.2; length of palatal 
slits, 4.6; width of palatal slits, 2.2; length of palate to palatal notch, 
12.4; length of upper molar series, 4.8; length of single half mandible, 
res, (Bangs, |. c.) 
45. Tylomys. 
IL—; i 1G, 
I—1” 
Tylomys Peters, Monatsb. K. Preuss. Akad. Wiss. Berlin, 1866, p. 
404. Type Hesperomys nudicaudus Peters. 
“Ears rather large, naked; tail and soles of feet naked. Skull with 
no raised supraorbital ridges, but with a broad horizontal edge over 
orbits; antorbital foramen not visible from above.’’ 
Ren VO rear Glib se 
A. Broad horizontal edge above orbits; ears 
large, naked; tail long. PAGE 
Meer PALS LETTUSINEOUS «04.0. 6 ee es a T. nudicaudus 217 
Meee er parts Cark, STAY 2) seu kpeg es Bee ee T. tumbalensts 218 
©, Upper parts pale gray? Specimen too 
Hom On be (CMATACTEMIZO Ns vik ee et ee he wa ee LT \oullaris 210 
d. Upper parts rufous fawn and black.......... T. watsont 219 
e€. Upper parts mouse color and black....... TI. panamensis 219 
195. nudicaudus (Hesperomys), Peters, Monatsb. K. Preuss. Akad. 
Wiss. Berlin, 1866, p. 404, pl. 1, figs. 1-4. 
NAKED-TAILED Rat. 
Type locality. Guatemala. 
Geogr. Distr. Southeastern Mexico (State of Chiapas), into 
Guatemala. 
Color. Upper parts ferrugineous, base of hairs plumbeous, under 
parts white; tail naked, basal half black, remainder yellow; hands 
and feet dusky. 
Measurements. Total length, 403.75; tail, 207.5. Skull: occipito- 
nasal length, 46; Hensel, 38; zygomatic width, 24; interorbital con- 
striction, 8.6; length of nasals, 14.8; palatal length, 19.3; length of 
mandible, angle to alveolus of incisor, 35; length of upper tooth 
row, 8.6. . 
