268 Mr. O. Thomas on 



breadth of brain-case 108; interparietal 2-8x8*8; anterior 

 zygoma-root 1*6 ; palate length from henselion 9*8 ; dia- 

 stema 6*5 ; palatal foramina 4'5x 2 ; length of upper molar 

 series 3*1. 



Bab. Pallatanga, Ecuador. 



Type B.M. no. 59. 11. 1. 11. Collected by L. Fraser, 

 December 1858. 



" Found among the bananas and plantains " (L. F.). 



The doubt as to its being 0. minutus being once settled in 

 the negative, there is no described species from which this 

 animal may not be readily distinguished by its thick fur, 

 rufous under surface, and narrow anterior zygoma-root. 



A second form of the same group occurs at Bogota, and 

 may be provisionally regarded as a subspecies of 0. dryas. 



Oryzomys dryas humiUor, subsp. n. 



Closely allied to the typical subspecies in all important 

 respects, but smaller (as shown by the skull and hind-foot 

 measurements) and less rufous in colour, the general tone 

 being a dull brownish yellow, this colour being, just as in 

 0. d. typicus, continued all over the belly, without any line 

 of demarcation on the sides. Fur shorter and more woolly 

 in texture. The ears are blacker, more in contrast with the 

 general colour. The skull is similar to that of 0. d. typicus, 

 but the supraorbital edges are less sharply square, there is 

 slightly more of an anterior projection of the zygoma-root, 

 and the palatine foramina are shorter. 



Dimensions of the type (an adult male in skin) : — 



Head and body (stretched) 90 millim. ,• tail 122; hind foot 

 (moistened) 20 ; ear 14. 



Skull: greatest length 26; basilar length 16*7; greatest 

 breadth 12*1; nasals 8*5x2"6; interorbital breadth 3"2 ; 

 breadth of brain-case 10"5; interparietal 3"3 x 8*5 ; anterior 

 zygoma-root 1*8; palate-length 9"2 ; diastema 6'1 ; palatal 

 foramina 4 x 1*7 ; length of upper molar series 3. 



Hob. Plains of Bogota. Coll. G. D. Child, May 10, 1895. 



Type B.M. no. 98. 7. 3. 3. 



Oryzomys flavicans subluteus, subsp. n. 



Similar to the typical subspecies * in size and general 

 characters, but distinguished by its darker belly. In 

 O.f. typicus, as exemplified in more than a dozen specimens 

 from the type locality, the under surface is whitish with a 



* Described in Ann. & Mag. Nat. Hist. (6) xiv. p. 861 (1894). 



