Mcrriam — Xew KaiKjaroo Rn.tAi. Ill 



breadth are essentially the same in the two species, but the naso-occii)itaI 

 lensj;th in onuitus is niiu-h less and thezy!>ouiatic breadth very much greater- 

 While the zygomatic breadth is actually greater in urnaluK, the breadth 

 across the to]) of the skull is decidedly less : hence when viewed from above, 

 the zygomatic arches stand out beyond the sides of the cranium, while in 

 jilnllipsi they are hidden beneath the edges of the frontals and parietals. 

 In oniatas the top of the cranium is much flatter than in phillipsi ; the 

 supraoccipital is narrower between the mastoid bulhc ; the nasals are not 

 nan-owed behind, and the ascending branches of the premaxilhe are shorter 

 and more slender and have no trace of the posterior expansion commonly 

 present in pliUUj^ii. The upper ]>remolar is a single prism and its crown 

 has no trace of the antero-internal lobe of jiliilliim. 



Dipodomys perotensis sp. nov. 



?///'f from Pekotk, ^'EKA Ckuz, Mexico. No. 54,285 ? ad. U. S. Nat. 

 Mus. Dei)artment of Agriculture Collection. Collected May 21, 1893 by 

 E. W. Nelson (Original number 4840). 



Measurements (taken in tlesh). — Type: Total length 265 ; tail vertebr;cl(j2 ; 

 hind foot 40. Ear from anterior base 14 (in dry skin). 



vlcemj/t' measurements of 8 specimens from type locality : Total length 

 271 ; tail vertebne 168 ; hind foot 40.4. 



General character-^ — Similar in size and general appearance to 

 Dipodomys phillipsi and ornatv.8 and intermediate between them 

 in coloration ; white terminal pencil short, and m one specimen 

 absent. Cranial characters substantial. 



Color. — Ui)per parts brownisli clay color, intimately mixed with and 

 darkened by blackish-tipped hairs on head and back ; strongly suffused with 

 ochraceous buff on sides and flanks; facial crescents large and black, meet- 

 ing across the nose ; inner side of leg and sole blackish ; lateral white stripes 

 of tail disappearing near junction of distal and middle thirds ; white termi- 

 nal pencil small and in one specimen absent (possibly the result of injury 

 in early life). 



CnmitiJ clMractera. — Skull similar to that of D. ormdas, but even narrower 

 on top [consequently very different from jiliUlipsi]; zygoma visible from 

 above ; top of skull more strongly arched anteroposteriorly than any other 

 known species ; breadth of supraoccipital between inflated mastoids greater 

 than in pldWpsi or ormdas. Angle of mandible larger than in phlUijisi but 

 smaller than in ornatus. 



Dipodomys merriami nevadensis subsp. nov. 



lype from Pyramid Lake, Nevada. No. 54,552 9 ad. U. S. Nat. Mus., 

 Department of Agriculture Collection. Collected June 26, 1S9:J, by Vernon 

 Bailey (Original number 3,990). 



Mc'L^urements (taken in flesh). —7Vy'e.- Total length 240 ; tail vertebne 140 ; 

 hind foot 39. Ear from anterior base 13 (in tlry skin). 



