140 Mr. 0. Thomas on 



obviously not Waterliouse's species of that name. Tlie 

 specimen liad liitlierto been taken for an Eligmodontia, but a 

 renewed examination shows that it is a Phyllotis allied to 

 Ph. amicus, and distinguishable by the characters described 

 above. 



6. Andinomys edax, Thos. 



S. 10, 23, 26, 28, 41, 44; ?. y, 20. Maimara. 

 2230 m. 



? . 59. Cerro de Lagunita, ]\Iaimara. 4500 m. 



Tliis distinct rat had previously only been obtained by 

 P. O. Simons, who got examples at La Paz and the neigh- 

 bourhood of Potosi. The mammary formula proves to be 

 2—2 = 8. 



" Lives in the branches of trees, where it makes its 

 nest."— ^. B. 



7. ATcodon jiicundus, sp. n. 



? . 46. Cerro de la Lagunita, E. of Maimara. 4500 m. 

 27th March, ]912. B.M. no. 12. 12. 12. 12. Type. 



A medium-sized pale buffy species, with very small 

 teeth. 



Size rather less than in A. alhiventer. Fur rather long ; 

 liairs of back about 10 mm. in length. Greneral colour above 

 pale buffy clay-colour, very much as in A. andinHs, paler on 

 the head, ricliest on the back ; sides and under surface paler 

 clay-colour (about as in A, spegazzinii), the bases of the 

 hairs slaty as usual. Ears sliort, hairy, dark greyish, an 

 inconspicuous whitish patch behind them. Hands and feet . 

 dull buft'y whitish, the claws of normal length. Tail grizzled 

 with black and greyish above, buffy whitish on sides and 

 below. 



Skull considerably smaller than that of either A. andinus 

 or alhiventer, about as in A. puer, low, smooth, rounded, with 

 broad unbeaded interorbital region. Bullae proportionally 

 rather large. Molars very small, conspicuously smaller than 

 in any of the allied species. 



Dimensions of the type (measured by collector) : — 



Head and body 90 mm. ; tail 62 ; hind foot 20 ; ear 15. 



Skull: greatest length 23'8; condylo-incisive length 22 ; 

 zygomatic breadth 12'3 ; nasals 9'5 ; interorbital breadth 

 4'1 ; breadth of brain-case 11"3 ; palatilar length 9*7 ; 

 palatal foramina 5'6; upper molar series 3*3. 



IJab. and Type as above. 



This pale buffy- bellied Akodon is very like A. andhius, 

 Philippi, externally, but its skull and teeth are nuiikedly 

 smaller than in the more southern species. 



