NEW HARVEST MICE 549 



pared with tenuirostris the skull is about two-thirds as large, the 

 rostrum relatively shorter and less upturned, the teeth very much 

 smaller. 



Measurements. — Type specimen (9 ad.): total length 185 mm.; 

 tail vertebrae 113; hind foot 31. 



Skull : basal length 17.5 ; zygomatic breadth posteriorly 11 ; length 

 of palate 10; length of molar series 3. 



REITHRODONTOMYS MICRODON ALBILABRIS subsp. nov. 



Type from Cerro San Felipe, Oaxaca, Mexico (altitude 10,000 ft.). 



No. 68393. 9 ad. U. S. National Museum, Biological Survey 



Coll. Aug. 35, 1894. E. VV. Nelson and E. A. Goldman. Orig. 



no. 6629. 



Characters. — Similar in size and general appearance to R. micro- 

 don., but very much paler, the upperparts fulvous instead of intense 

 ferruginous; lips, sides of nose, and underparts pure white instead of 

 salmon. The skull differs slightly from that of microdon : braincase 

 larger, more inflated ; zygomata broader anteriorly ; incisive foramina 

 shorter; bullae less inflated and more flattened on outer side; molars 

 slightly larger and heavier. 



Measurements. — T3'pe specimen (9 ad.) : total length 187 mm.; 

 tail vertebrae 117; hind foot 20. 



Skull: basal length 17; zygomatic breadth posteriorly 11.5; length 

 of palate 10; length of molar series 3. 



REITHRODONTOMYS CHRYSOPSIS TOLUC^ subsp. nov. 



Type from north slope of Volcan Toluca, State of Mexico (altitude 

 11,500 ft.). No. 55895. 9 ad. U. S. National Museum, Biological 

 Survey Coll. Sept. 10, 1893. E. W. Nelson and E. A. Gold- 

 man. Orig. no. 5454. 



Characters. — Similar to chrysopsis^ but top of head and upper 

 parts generally much darker, more profusely and finely mixed with 

 black tipped hairs; sides duller and much less fulvous; tail shorter; 

 underparts whitish, the plumbeous underf ur showing through ; hind 

 feet brownish to near base of toes. Skull similar to that of chry- 

 sopsi's, but slightly smaller and narrower, with even more slender 

 rostrum, slightly smaller bullae, and slightly smaller molars. Ex- 

 ternally the resemblance to perotensis is much closer than to chry- 

 sopsis, but the skull is quite different from that of perotensis and very 

 close to chrysopsis. 



Measurements. — Type specimen (9 ad.): total length 180 mm. ; 

 tail vertebrae 98; hind foot 21. 



