NEW HARVEST MICE 55 1 



distinctly bicolor. The skull is nearer that of perotcnsis^ from which 

 it differs as above pointed out. 



Measurements. — Type specimen {$ ad.) : total length 1S2 mm.; 

 tail vertebrae 105 ; hind foot 20. 



REITHRODONTOMYS COLIMyE sp. nov. 



Type from near timberline, Sierra Nevada de Colima, Jalisco, 



Mexico (altitude 12,000 ft.). No. fffH- ^ ^^' U. S. National 



Museum, Biological Survey Coll. April 21, 1S92. E. W. Nelson 



and E. A. Goldman. Orig. no. 2447. 



Characters. — Size smallest of the chrysopsis group; ears large 

 and dark ; tail rather short and sharply bicolor ; pelage soft and woolly ; 

 similar in general to chrysopsis but decidedly smaller and with dis- 

 tinctive cranial characters. 



Color. — Upperparts varying from buffy fulvous to bright golden 

 fulvous strongly darkened on top of head and back by dark tipped 

 hairs ; underparts buffy salmon ; wrists and ankles dark ; fore feet 

 whitish; hind feet brownish, becoming whitish toward toes; tail 

 dusky above, whitish below, with distinct line of demarcation. 



Cranial characters. — Skull similar to that of chrysopsis tolucce but 

 decidedly smaller, with nasals ending on plane of premaxillae instead 

 of anterior to this plane ; zygomata slightly more squarely spreading 

 anteriorly ; rostrum slightly shorter and broader ; incisive foramina 

 more broadly open ; molar series same size, measuring about 3.6 mm. 



Measuremejits. — Type specimen ( $ ad.): total length 165 mm.; 

 tail vertebrcE 90 ; hind foot 20. A female from type locality : total 

 length 166; tail vertebrae 90; hind foot 20. 



REITHRODONTOMYS COLIM^^ NERTERUS subsp. nov. 



Type from foothill region of Sierra Nevada de Colima, Jalisco, Mexico 

 (altitude 6,500 ft.). No. fffff. $ ad. U. S. National Museum, 

 Biological Survey Coll. April 21, 1892. E. W. Nelson and E. 

 A. Goldman. Orig. no. 2514. 



Characters. — Similar to colimce^ but tail decidedly longer and less 

 distinctly bicolor; pelage much shorter and coarser (not soft and 

 woolly) ; skull slightly smaller, with smaller molars (molar series 

 measuring 3.3 instead of 3.6), 



Remarks. — This animal is particularly interesting in showing the 

 changes that take place when a member of the chrysopsis group 

 descends from the high altitudes at which all of the species live. The 

 specimens of typical colimce collected by Nelson and Goldman were 

 found at altitudes of 10,000 and 12,000 feet, while those of the 



