252 Mr. O. Thomas on 
haired, the scales not hidden; brown above, white below, 
especially proximally. 
Skull stoutly built and quite unlike that of any of the 
allied species in the great development of the supraorbital 
ridges, which are expanded and overhanging somewhat as 
in the otherwise very different O. chrysomelas, Allen. The 
frontal region is strongly concave on each side internal to the 
ridges, which project about 14 millim. outwards and slightly 
upwards. Behind the ridges pass round across the parietals 
in the usual way. Muzzle rather heavily built. Nasals 
evenly tapering backwards, ending just level with the pre- 
maxillary processes. Palatal foramina small, not reaching to 
the level of the molars. Molars light and delicate. 
Dimensions of the type (measured in the flesh) :— 
Head and body 140 millim.; tail 142; hind foot, s. u. 27, 
Gy Wo ABMS Gare It. 
Skull: tip of nasals to back of interparietal 33; greatest 
breadth 17; nasals 11°6 x4; interorbital breadth 6°5; palate 
length 13°8; diastema 81; palatal foramina 5 x 2°2; length 
of upper molar series 4:9. 
Hab. Bogava, Chiriqui, Panama. Altitude 250 m. 
Type. Male. B.M. no. 0. 7. 11.43. Original number 64. 
Collected 15th September, 1898, by Mr. H. J. Watson. 
The striking characters of colour and skull-structure will 
readily separate this fine species from any of its congeners. 
Oryzomys panamensis, sp. D. 
A rich fulvous member of the O. laticeps group. 
Size about as in other members of the group. Fur close, 
crisp, and velvety ; hairs of back about 6-7 millim. in length. 
General colour above bright tawny or tawny ochraceous from 
nape to tail, finely lined with blackish on the back, brighter 
and clearer on thesides. Head more greyish. Under surface 
soiled grey, fairly sharply defined, the hairs short, their basal 
halves everywhere slaty and their terminal white. ars 
short, rounded, very finely haired, uniformly brown. Outer 
sides of arms and legs greyer than body, inner sides like 
belly; hands and feet whitish above; palms and soles pale 
flesh-colour. ‘Tail of medium length, thinly haired, the scales 
not hidden ; pale brown above and white below. 
Skull in size and proportions very like that of O. velutinus, 
All, & Chapm. Nasals very narrow, evenly tapering back- 
wards. Supraorbital edges sharply and finely beaded, 
without heavy ridges. Palatal foramina short, not nearly ~ 
reaching to the molars. Molars small, narrow, and delicate. 
