242 Mr. 0. Thomas oti 



Skull as in aJhiguJaris, but the palatal foramina shorter. 



Dimensions of tlie type (measured in flesh) : — 



Head and body 140 mm. ; tail 162 ; hind foot 34 ; 

 ear 20. 



Skull : greatest length 34*8 ; condj-lo-incisive length 31'8 ; 

 zygomatic breadth 18 ; nasals 12"5 ; interorbital breadth 5 ; 

 breadth of brain-case 14 ; palatilar length 15'3 ; palatal 

 foramina 4*6 ; upper molar series 5*7. 



Bah. MIndo, ]S'.W. of Qiiito, Ecuador. Alt. 4200'. 



Type. Adult male. B.M. no. 13. 10. 24. 43. Original 

 number 113. Collected 4r]i June, 1913, by Gilbert Ham- 

 mond. Presented by Oldtield Tliomas. Sixteen specimens. 



While Dr. Allen's 0. pectoralis from the Cauca and the 

 typical 0. albigul'iris are almost precisely like each other in 

 colour, this form from Mindo differs from both by its much 

 darker hue, and especially by its blackened dorsal area. Its 

 very short palatal foramina are also characteristic. 



Oryzomys caracolus, sp. n. 



A small species allied to 0. meridensis. 



Size decidedly less than in 0. meridensis and its near 

 relatives macidiventer and tamcp, but larger than in the 

 Trinidad velutirnis. Fur soft and fine, hairs of back about 

 10 mm. in length. General colour greyish brown washtd 

 with fulvous on sides, darker brown on median dorsal area. 

 Below grey washed with creamy white, just as in 7neridensis, 

 but there is less tendency to the formation of white pectoral 

 patches, only one specimen of three having such a patch at 

 all, and that a very small one. Head grey, without fulvous 

 intermixture. Hands and feet slender, pale grey colour, the 

 hairs silvery white. Tail very finely haired, grey above, 

 white below, the two colours not sharply contrasted. 



Skull smaller than in meridensis. Interorbital region flat 

 above, its edges with a greater tendency to iiave a supra- 

 orbital bead, instead of being rounded, as is usually the case 

 in meridensis. P;;latal foramina comparatively rather long. 

 Molars smaller than in meridensis, much larger than in 

 velutinus. 



Dimensions of the type (measured in tlie fle-h) : — 



Head and body 131 mm. ; tail 144; hind foot (s. u.) 31 ; 

 ear 23. 



Skull : greatest length 33*2 ; condylo-incisive length 29*7 ; 

 zygomatic breadth 17 ; nasals 12*5 ; interorbital breadth 5 ; 

 breadth of brain-case 14; palatilar length 14*5; palatal 

 foramina (j'2 ; upper molar series 5. 



