small Mammals from Nicaragua and Bogota. 59 
darker and less brilliant than in that species. As to its real 
affinities, I am unable to speak with certainty, but it seems 
to be one of the group of Oryzomys which show a tendency 
towards Rhipidomys, although, so far as I know, there is no 
described species with which it could possibly be confounded. 
2. Oryzomys Childi, sp. n. 
Size medium. Fur rather long (11-12 millim. on back), 
straight, of medium texture. General colour dull grizzled 
grey-brown, the hairs dark slate, with pale brown tips. On 
the middle part of the back all the hairs are without brown 
tips, and the slate-colour being here specially dark, a long 
oval blackish patch is formed. Under surface greyish white, 
the tips of the hairs white; line of demarcation fairly well 
defined. ars large, finely haired, black. Feet long, 
whitish above, a faint brownish discoloration on the meta- 
tarsals ; fifth hind toe, without claw, reaching just past the 
middle of the first phalanx of the fourth. Tail long, slender, 
thinly haired, bicolor, brown above, whitish beneath. 
Skull smooth, rounded, and little ridged. Interorbital edges 
rounded, not beaded. Palatal foramina rather short. Molars 
as in typical Oryzomys. 
Dimensions of the type (an adult female skin) :— 
Head and body 131 millim.; tail 143; hind foot 31; 
ear (c.) 16. 
Skull: front corner of interparietal to tip of nasals 29:5; 
greatest breadth 168 ; nasals 12 x 3:7; interorbital breadth 5 ; 
length of zygomatic plate 3°8 ; palate length from henselion 
14:2; diastema 8°5; palatal foramina 56x 2-4; length of 
upper molar series 5:5. 
O. Childi is by the shape of its skull evidently closely 
allied to O. mertdensis, Thos., from which it mainly differs 
by its dull brown instead of rufous coloration, longer fur, and 
its blackish dorsal area. 
The name of this species is given in honour of Mr. George 
D. Child, through whose kind instrumentality the specimens 
have been obtained. 
3. Oryzomys laniger, sp. n. 
Fur long, hairs on back about 12 millim. in length; very 
soft and fluffy. General colour above dull olivaceous grey ; 
the hairs dark slate for nine tenths of their length, their tips 
olive. Under surface similar, but paler, the tips of the hairs 
dull yellowish ; line of demarcation not defined. ars fairly 
large, naked. Metapodials brown mesially, their edges and 
