68 



NORTH AMERICAN FAUNA, 



[No. 36. 



and is apparently the only form having an extensive range. Speci- 

 mens from Mount Tancitaro and Patamban show no characters to 

 distinguish them from the typical form. From B. /. toltecus, which 

 occupies the valley of Mexico, cTirysopsis differs in larger size, richer 

 colors, longer pelage, and blacker ears, as well as in cranial char- 

 acters. 



On Mount Popocatepetl, Nelson and Goldman found this species 

 occurring sparingly in grassy places in the open forest from the base 

 of the mountain up to 12,000 feet. On Mount Patamban it was most 

 numerous at about 11,000 feet in the upper part of the Canadian 

 Zone, a few ranging to the extreme summit above 12,000 feet. In the 

 upper part of its range it was found among grass and brush. 



Specimens examined. — Total number, 25, from the following locaH- 

 ties in Mexico: 



Mexico: Ajusco (11,000 feet), 3; Mount Iztaccihuatl (13,500 feet), 1; Mount 



Popocatepetl (11,500 feet), 3; Salazar (9,000 feet), 1. 

 Morelos: Huitzilac (10,000 feet), 1. 



Michoacan: Mount Tancitaro (10,000-12,000 feet), 7; Patamban (11,000 feet), 9. 



REITHRODONTOMYS CHRYSOPSIS TOLUC^ Merriam. 



ToLUCA Harvest Mouse. 



Reithrodontomys chrysopsis tolucse MenisLm, Proc. Wash. Acad. Sci., Ill, 1901, p. 549. 



Type locality. — North slope of Volcan Toluca, Mexico (altitude, 

 11,500 feet). 



Distribution. — Known only from the type locality. 



Characters. — Similar to clirysopsis, but slightly smaller and much 

 less intensely ochraceous; skull slenderer. 



Color. — Worn pelage: Upperparts mixed black and ochraceous- 

 tawny with a well-defined black median band, as in clirysopsis, but 

 lacking almost entirely the bright golden color shown by the latter; 

 ears fuscous; front feet huffy white, with a band of hair-brown 

 reaching half way to the toes; hind feet soiled whitish, tinged with 

 dusky; ankles fuscous; ring around eye blackish; underparts grayish 

 with scarcely a trace of buff; tail hair-brown above, grayish white 

 below. 



SJcull. — Slightly smaller than that of cTirysopsis; braincase nar- 

 rower; rostrum slenderer, much narrowed at the tip; bullae much 

 smaller; subsidiary enamel loops of upper molars low and slightly 

 developed; accessory tubercles absent. 



Measurements. — Type: Total length, 180; tail vertebrse, 98; hind 

 foot, 21. Skull: (See table, p. 81). 



Remarlcs. — This form, known from only a single specimen, has 

 rather pronounced characters. On account of the worn condition 

 of the type specimen, the colors can not be satisfactorily described. 

 Specimens in fresh pelage will doubtless prove less different from 



