Mummahfrom Bolivia. 135 



bases sliowinfj tlirough ; lines of demarcation not sharply 

 doHned. Face lined (rreyisb. Ears not contrasting witli the 

 general colour ; an indistinct postauricular light patch present. 

 Upper surface of head and feet dull whitish ; fifth iiind toe 

 without claw reaching to about the middle of ti)e basal phalanx 

 of the fourtli. Tail about the length of the body without the 

 head, well-haired, but the distinct rings of scales showing 

 through ; blackish above, dull white below. 



Skull markedly different from that of most Akodons in its 

 general build, which more resembles that found in Zijgo- 

 dontomys. Tipper outline strongly bowed. Nasals narrow, 

 eveidy converging backwards, extending just beyond the 

 premaxillary processes. Interorbital region flat transversely, 

 convex longitudinally, sharply square-edged, though not 

 ridged. Palatal foramina extending back to the middle of 

 m^ ; posterior palatal opening square, level with the back 

 of »?j'. 



Dimensions of the type : — 



Head and body 100 millim. ; tail 80 ; hind foot, s. u. 2'5, 

 c. u. 24-5 ; ear 19. 



Skull : greatest length 29 ; basilar length 23 ; zygomatic 

 breadth 15; length of nasals 11; interorbital breadth 5; 

 breadth of brain-case 12'4 ; palate length 12*5; diastema 8; 

 length of palatal foramina 6"8 ; length of upper molar series 

 (worn) 5. 



Hah. Cochabamba and the high grounds west of it. 



Type. Old female. Original number 1420. Collected 

 20th April, 1901. 



This distinct species has more the look of a small Zygo- 

 dontomys than an Ahodon, but its teeth prove it to be a 

 member of the latter genus. In its greyer phase it has some 

 resemblance also to A. hirtus, but its skull is widely different. 



19. Akodon pacijicus, sp. n. 



c?. La Paz, 4000 m. 28th February, 1901. 



(?) $ . Cochabamba, 2600 m. 25th April, 1901. 



(?) 2 ? . Choro. 3500 m. 8th to 10th May, 1901. 



Oetieral appearance of A. olivaceus and mollisj but skull 

 markedly different. 



Size comparatively large. Fur close and thick and rather 

 coarse; hairs of back about 11 millim. in length. General 

 colour above pale olivaceous grey, not so strongly tawny as 

 in the smaller species A. puer. Sides rather more yellowish. 

 Under surface soiled greyish, with buffy tips, not sharply 

 defined laterally. Eyes with yellow rings. Ears of medium 



