1914.] 



KEITHRODOls^TOMYS CHKYSOPSIB GEOUP. 



69 



cJirysopsis than is this worn individual, but the underparts apparently 

 are distinctly whiter. 



Specimen examined. — One, the type. 



KEITHRODONTOMYS CHRYSOPSIS ORIZABA Merriam. 



Mount Orizaba Harvest Mouse. 



Reithrodontomys orizahx Merriam, Proc. Wash. Acad. Sci., Ill, 1901, p. 550. 



Type locality. — Mount Orizaba, Puebla, Mexico (altitude, 9,500 

 feet). 



Distribution. — Known only from the type locahty. 

 Characters. — ^Externally the same as cJirysopsis ] skull narrower and 

 bullae smaller. 



Color. — ^As in cJirysopsis. 



SJculU — Apparently smaller than that of cJirysopsis, but length of 

 skull and shape of zygomata not known; braincase narrower, audital 

 bullae decidly smaller; molar series and nasals shorter; subsidiary 

 enamel loops of well developed, of present but shorter. Com- 

 pared with tolucse: Braincase and bullae similar; rostrum broader. 



Measurements. — Type: Total length, 182; tail vertebrae, 105; hind 

 foot, 20. Skull: (See table, p. 81). 



RemarJcs. — This form so closely resembles cJirysopsis in color that 

 it seems best to consider it a subspecies of the latter; in cranial 

 characters it more nearly resembles tolucse. Additional material is 

 necessary to determine its true relationship. 



Specimen examined. — One, the type. 



REITHRODONTOMYS PEROTENSIS Merriam. 



Perote Harvest Mouse. 



Reithrodontomys perotensis MeiTLa,!!!, Proc. Wash. Acad. Sci., Ill, 1901, p. 550. 



Type locality. — Cofre de Perote, Vera Cruz, Mexico (altitude, 9,500 

 feet). 



Distribution, — Known only from the type locality. 



CJiaracters. — Externally similar to cJirysopsis, but color of upper- 

 parts less intensely ochraceous; skull smaller with much smaller 

 bullae. 



Color. — Upperparts cinnamon with strong tinge of ochraceous, 

 extensively mixed with black and with a distinct median band of 

 the latter color; ears fuscous, somewhat paler than in cJirysopsis; 

 underparts strongly washed with light pinkish cinnamon; tail pale 

 fuscous above, slightly whitened beneath. 



SJcuU. — Smaller than that of R. c. cJirysopsis, with flatter braincase 

 and smaller bullae; zygomata squarely spreading anteriorly, nearly 



1 The type and only known specimen is badly broken. 



