neio Cryptotis, Thomasomj's, and Oryzomjfi. 355 



Skull rather shorter and more robust than in meriden^h, 

 the muzzle shorter and the interorbital region broader. As 

 an indicalion of the shortening of tlie muzzle, the distanci- 

 from the back of i^ to the front of ;/ is only 2*0 mm. as com- 

 pared with 2*6 in the type of meridensis. Brain-case moie 

 inflated upwards, a marked angle at the junction of brain- 

 case and face. 



Anterior upper incisor shorter and more proclivous ; large 

 unicuspid.s more vertical, less oblique, in order to crowd into 

 the shorter space available. 



Dimensions of the type, taken on the skin : — 



Head and body 92 mm. ; tail 30; hind foot 15. 



Skull : condylo-basal length 21"7 ; condylo-incisive length 

 22*7 ; interorbital breadth 5'3 ; breadtii across brain-case 11 ; 

 length from nasal notch to foramen above olfactory fossa 9'2 ; 

 upper tooth-series 10; front of;/ to back of m^ 5'8. 



Hah. Medellin region of Colombia : type from San Pedro, 

 30 km. north of Medellin. 



Type. Adult male. B.M. no. 21. 7. 1. 9. Original num- 

 ber 10. Collected December 1919 by Frere Niceforo Maria. 



The Panama Crijptolis described by Mr. Goklman as 

 C. merus is considerably smaller than G. medelUaius. 



Thomasomys nice/ori, sp. n. 



Near T. aureus, but smaller and with smaller teeth. 



General appearance very much as in 7'. aureus, tlioigh 

 the head and fore back are rather less richly fulvous, bur the 

 colours are essentially the same, with the same butfy or 

 ochraceous suffusion above, becoming richer on the rump, 

 and with the same buffy Avashing of the belly. Feet com- 

 paratively light and delicate, buffy whitish, with darker 

 patches on wrists and metacarpals, ankles and metatarsals. 

 Tail well haired, uniformly brown, not so long as in the 

 allied species. 



Skull smidler throughout than in T. aureus, \\\q.vq{oxq much 

 smaller than in T. princeps of Bogota. Muzzle slender; 

 nasals narrow. Interorbital region comparatively broad, less 

 sharply defined and ridged than in the other species. Palatal 

 foramina as usual larger and open. Molars small and 

 delicate, both shorter and narrower than in the other members 

 of the group. 



Dimensions of the type, measured on the skin : — 



Head and body 150 mm.; tail 187; hind foot (wet) 32 ; 

 ear 19. 



Skull : greatest length 36'5 ; condylo-incisive length 33*8 ; 

 zygomatic breadth 19 ; nasals 13*2 X 1 ; interorbital breadth 



23* 



