obtained on the Rio Joraao. 529 
Size rather less than in O. subflavus. Fur soft, close, and 
straight; hairs of back about 11 millim. in leneth. General 
colour a beautiful ochraceous buff, brilliant and clear on the 
cheeks, flanks, and hips, more or less lined with black on the 
back; in the oldest and brightest specimens the middle area 
of the back is lined and coloured about as in O. flavicans 
(though of a less reddish tinge), but the bright ochraceous 
buffy of the flanks is unrivalled in any species known to me. 
Under surface sharply defined white, the bases of the hairs 
slaty, except just on the chin and scrotal region, where the 
hairs are wholly white. Head like back, top of muzzle 
slightly greyer. ars large, finely haired, pale brown, con- 
trasting but little with the head. Front of fore limbs like 
body to wrist, remainder and whole upperside of hands 
white ; hind limbs buffy above, the upper surface of the feet 
also tinged with buffy. Tail nearly naked, the hairs 
excessively short and fine; unusually finely scaled, the rings 
running nearly 20 to the centimetre; above brown, beneath 
white, darkening towards the tip. 
Skull heavily built, with broad muzzle and broad inter- 
orbital region, whose edges are sharply square or have a fine 
beading along them, but are without overhanging ridges. 
Palatal foramina rather longer than the molar series, not 
widely open, their posterior end some distance in front of m’. 
Palate ending some way behind m’. 
Dimensions of the type, taken in the flesh :— 
Head and body 145 millim.; tail 153 ; hind foot (s. u.) 33; 
ear 23. 
Skull: greatest length 36 ; basilar length 28°2 ; zygomatic 
breadth 19°35; nasals 15x4°5; interorbital breadth 6:1; 
palate length 16°4 ; diastema 9°7 ; palatal foramina 6°3 x 2°3 ; 
length of upper molar series 5:5. 
Type. Male (old). B.M.no.1.11.8.82. Original number 
744, Collected 10th July, 1901. 
This beautiful species seems widely different from any 
Oryzomys hitherto described from South Brazil. Perhaps 
its nearest ally is O. intermedius, Leche *, which is, however, 
much less brilliantly coloured, and has a slenderer skull 
with narrower nasals and narrower interorbital region. 
Of this latter animal Mr. Robert has sent home, in his 
earlier collections, quite a series of specimens from Piqueté 
and Cruzeiro, in the eastern part of S&o Paulo, the species 
no doubt ranging along the region of the Serra do Mar, from 
* Hesperomys laticeps, var. intermedia, Leche, Zool. JB. i. p. 693 
(1886). a 
Ann. & Mag, N. Hist. Ser. 7. Vol. vin. ot 
