.NO. 2333. MAMMALIA COLLECTED IN PERU BY HELLER— THOMAS. 239 



Three specimens, all from Ollantaytambo (Nos. 194685-6,195092). 



This species is less typically Ghroeomys-MkQ in all the characters 

 used to distinguish that genus from other members of the Akodon 

 group; for the coloration is less abnormal, the claws are less elon- 

 gated, the incisors are darker colored, and the bullae are smaller 

 than in the hitherto known species of the genus. There is, however, 

 no question that it is a Chroeomys^ and that its nearest alliance is 

 with G. fulchemmus cniceri^ with which it most nearly agrees in 

 general color. 



47. OXYMYCTERUS PAKAMENSIS Thomas. 



Three specimens, as follows : 

 Chospyoc, 10,000 feet, 1 (No. 194699). 

 Ollantaytambo, 13,000 feet, 2 (Nos. 194700, 194703). 

 Quite indistinguishable from the typical specimens of this species 

 which came from Choquecamate, northwest Bolivia. 



48. mCROXUS TORQUES Thomas. 



1917. Microxus torques Thomas, Smiths. Misc. Coll., vol. 68, No. 4, p. 3. 

 April 10, 1917. 



Like M. mimus, but the zygomatic plate not so strongly narrowed 

 and slanting. Also superficially like Akodon surdus. 



Size averaging slightly greater than in M. mwmis. Fur close, soft, 

 and woolly; hairs of back about 10 mm. in length. General color 

 smoky or olivaceous gray, quite as in M. mhnus, and also very similar 

 to the color of Akodon surdu^^ although, owing to the softer texture 

 of the hair, there is a difference in appearance. Under surface little 

 lighter than upper, a vague darker streak often present in the sternal 

 region. Ears rather short, colored like head. Hands and feet gray- 

 ish brown above; soles flesh-colored, not blacldsh, as in Akodon 

 surdus. Tail long, finely haired ; brown above, scarcely lighter below. 



Skull (pi. 15, fig. 4), as compared with that of M. mimus, very 

 similar in most respects. Upper profile not perhaps quite so flattened 

 in the frontal region, and therefore more approaching the even con- 

 vexity found in Akodon surdus. Interorbital space broad, smooth, 

 its edges scarcely squared. Zygomatic plate decidedly broader than 

 in M. mimus; its front edge, although distinctly slanting, yet not so 

 slanting as in mimus, and with a certain slight convexity in its upper 

 third; this part therefore tending toward the condition found in 

 Akodon. Palatal foramina well open, ending opposite the anterior 

 third of first molar. 



Dimensions of i^yp^.— Head and body, 102 mm. ; tail, 94 ; hindf oot, 

 22.3 ; ear, 17. Skull— greatest length, 28 ; condylo-incisive length, 25 ; 

 zygomatic breadth, 14.3; nasals, 10.2 by 3; interorbital breadth, 5; 

 breadth of brain case, 12.5 ; zygomatic plate, 2 (1.5 in the type of 



