Osgood — Thirty New Mice of the Gemts Peromysais. 73 



Color. — Almost exactly as in P. lophiinis ; dark markings of feet and 

 face slightlj' niore intense; tail chiefly brown, but with a narrow line of 

 wliite on under side. 



Shnll. — Size very small ; similar in general to that of P. lophurus, hnt 

 with more inflated braincase and depressed rostrum ; audital bullfe rela- 

 tively larger; interorbital constriction relatively wider; teeth very small. 



Mensuremcnl!^. — Type: Total length, 169; tail vertebrse, 87 ; hind foot, 

 21: ear from notch, 14.;>. Skull: Greatest length, 24.4; basilar length 

 of Hensel, 18; zygomatic width, 12.5; interorbital constriction, 4.3 ; in- 

 terparietal, 8.2 X o; nasals, 9; bony palate, 3.5; palatine slits, 4.6 x 1.7; 

 diastema, 6; postpalatal length, 8; upper molar series, 8.9. 



Remarks. — This small species is not closely related to any known spe- 

 cies except P. ln]>hHr>i>t, of which it is almost an exact miniatuie. Its 

 skull is even smaller than that of P. melimotis, which occurs in the same 

 region. It has, however, no relationship whatever to vie/nnolis. Its 

 small size, crested tail, and dark brown feet are amply sutRcient to dis- 

 tinguish it from all other known species. 



Peromyscus melanocarpus sp. nov. 



Ti/pe from Mount Zempoaltepec, Oaxaca, Mexico (altitude 8000 feet). 

 Young adult, No. 68,610, U. S. National Museum, Biological Survey Col- 

 lection, July 8, 1894, E. W. Nelson and E. A. Goldman. 



Characters. — Similar to P. megalops, but smaller and darker colored ; 

 hind feet slightly darker; fore feet decidedly more so, the blackish ex- 

 tending to base of digits; tail usually dusky all around or with only 

 traces of paleness beneath ; pelage long and soft. 



Color. — Ad. (^ No. 68,627, July 17: General effect of upper parts dark 

 blackish munnny brown, slightly darker along middle of l)ack ; actual 

 color of subterminal zone of hairs cinnamon rufous, which is almost lost 

 in the general effect by the many black -tip})ed hairs and the dark plum- 

 beous undercolor which shows through the thin subterminal zone; under 

 parts deep blackish slate washed with creamy white, producing an effect 

 which varies from. olive gray to slate gray ; pectoral region usually rich 

 cinnamon rufous; an intense black line extending from nostrils through 

 base of whiskers and eye; tail covered with short, bristly, blackish hairs 

 scarcely paler below than above; scales of tail usually dusky all around, 

 .sometimes with slight irregular patches of paler; fore and hind feet 

 dusky brownish to base of toes. 



Skull. — Apparently very similar to that of megalops; nasals slightly 

 shorter and more compressed j)Osteriorly ; superficially similar to totou- 

 tepecus, but differing as follows : nasals shorter and nearly always ending 

 in advance of the orbits about on a plane with the infraorbital foramen ; 

 frontal wider and with decidedly greater development of supraorbital 

 shelves; braincase wider ; anterior palatine foramina much longer ; molar 

 teeth larger. 



