55: 



MERRIAM 



present form were from four to five thousand feet lower. Externally 

 subspecies iterterus appears to be slightly larger than the high moun- 

 tain form, but the difference is mainly due to the greater length of 

 tail [the skull is actually smaller than that of coU»icc\. The pelage 

 has lost the soft, woolly quality characteristic of the chrysopsis series 

 and has become much shorter and coarser, resembling the ordinary 

 members of the genus. 



Measjirc7)ie7tts. — Type specimen ( 9 ad.) : total length 190 mm. ; 

 tail vertebra; iio; hind foot 20. Average of 3 adults from type lo- 

 cality: total length 186; tail vertebric 105: hind foot 20.5. 



REITHRODONTOMYS COSTARICENSIS JALAP.^ 

 subsp. nov. 



Type from alapa, Vera Cruz, Mexico (altitude 4,000 ft.). No. 



10S538. $ ad. U. S. National Museum, Biological Survey Coll. 



May 10, 1901. E. W. Nelson and E. A. Goldman. Orig. no. 



14712. 



Characters. — Similar to costaricctisls^ but paler anteriorly and with 

 greater admixture of black hairs on the back; hind feet grayish 

 brown throughout, including toes, without distinct white edgings; 

 hairs at base of claws white; ankles distinctly darker than feet; side of 

 nose, upper lip (broadly), and underparts white, tlie plumbeous under- 

 fur showing through except on chin and nose patch ; skull similar to 

 that of co^/ar/ctf/w/'^, but rostrum slightly shorter; braincase slightly 

 more inflated; nasals truncate posteriorly about i mm. in front of 

 ends of premaxilljE. 



Meas7irc7ncnts. — Type specimen ( $ ad.) : total length 197 mm. ; 

 tail 1 19 ; hind foot 21. 



REITHRODONTOMYS GOLDMANI sp. nov. 



Type from Metlaltoyuca, Puebla (altitude 800 ft.). No. 93096. 

 9 ad. U. S. National Museum, Biological Survey Coll. Feb- 

 ruary 12, 1898. E. A. Goldman. Orig. no. 12 153. 

 Characters. — Size small, similar to costar7'ce7tsis^ but very much 

 paler; ears smaller and brownish instead of blackish; tail shorter. 



Color. — Upperparts uniform ochraceous fulvous not noticeably 

 darkened by black hairs, but darkest on crown of head between 

 ears; palest between eyes; sides of nose, upper lip (broadly), chin and 

 underparts white ; fore feet whitish ; ankles and hind feet brownish, 

 the brown fading insensibly into whitish of toes; tail dusky all round. 

 Cra7iial characters. — Skull similar to that of costarice7isis but in- 

 cisive foramina shorter and less expanded in middle; molar series 

 slightly shorter. 



