Mammals from South America. 369 
of the back, apparently nearly entirely composed of wool- 
hairs, but with a few longer hairs intermixed. Colour uniform 
dark slaty grey, the hairs being almost wholly of this colour, 
but with their evtreme tips whitish grey. Ears of medium 
size, naked, grey. Under surface quite like back. Hands 
and feet brown; fifth hind toe reaching to the base of the 
second phalanx of the fourth. Tail long, slender, thinly 
haired, uniformly brown. 
Skull delicate, with a large rounded brain-case and small 
slender muzzle. Nasals narrow, evenly converging back- 
wards. Interorbital space smooth, its edges just showing a 
trace of squareness. Upper incisors unusually thrown for- 
wards, so that in a vertical view of the skull they are clearly 
visible in front of the nasals ; no part of their profile, even at 
their tips, slanting backwards towards the-mouth, as is usually 
the case. Lower incisors long and very slender. Palatal 
foramina very short, not nearly reaching to the level of ™. 
Molars of the squarish form typical of Oryzomys. 
Measurements of the type (in skin) :— 
Head and body 99 millim.; tail 130; hind foot (moist- 
ened) 22°7; ear (moistened) 14:1. 
Skull: basal length 21; basilar length 19°8; basion to tip 
of nasals 21'2; basion to tip of incisors 21°3; greatest breadth 
13°6 5 nasals 8°6 x 2°7 ; interorbital breadth 4°6 ; interparietal 
3x7; anterior zygoma-root 2°2; diastema 7°1; palatal 
foramina 3°5 x 1:9; length of upper molar series 3°7. 
Hab. Bogota. Coll. G. D. Child. 
This remarkable species is only placed provisionally in 
Oryzomys, and may hereafter prove to represent a peculiar 
group. It is distinguished from all others by its forwardly 
projecting incisors, rounded supraorbital edges, and_ short 
palatine foramina. ; 
Acodon bogotensis, sp. n. 
Intermediate in size between A. caliginosus and A. teguina, 
both of which it resembles in its uniformly finely grizzled 
blackish-brown colour. Ears of medium size, black. Limbs 
and tail dark brown. Belly scarcely lighter than back. 
Fifth hind toe reaching to the end of the first phalanx of the 
fourth. 
Skull with a narrow muzzle and broad interorbital region, 
whose edges are almost square, not rounded. Palatine fora- 
mina reaching just to the front edge of ™4. Outer wall of 
anteorbital foramina unusually short. Molars small in pro- 
portion to the general size. 
Ann. & Mag. N. Hist. Ser. 6. Vol. xvi. 26 
