1914.] 



REITHEODONTOMYS MEGALOTIS GROUP. 



37 



difficilis in Vera Cruz, and the two may occur together in some 

 localities. They are closely similar in general appearance, but 

 saturatus may be distinguished by its blacker ears and back, whiter 

 miderpartS; and larger skull. Specimens from Oaxaca City are redder 

 than tjrpical specimens, with less black on the dorsal area, but two 

 from the mountains west of Oaxaca are typical. 



S'pecimens examined. — Total number, 68, from the following locali- 

 ties in Mexico : 



Vera Cruz: Huauchinango, 1; Las Vigas, 11; Motint Orizaba, 2;^ Perote, 6; 

 Xuchil,7.i 



Hidalgo: Tulancingo, 1. 



Mexico: Salazar, 6; Toluca Valley, 2; Volcan Toluca, 1. 

 Morelos: Huitzilac, 3. 

 Michoacan: Nahuatzin, 9. 

 Jalisco: Ocotlan, 3. 



Oaxaca: Mount Zempoal tepee, 4; mountains 15 miles west of Oaxaca, 2; moun- 

 tains near Ozolotepec, 1; Oaxaca City, 6; Tamazulapam, 1; Tlapancingo, 2. 



REITHRODONTOMYS MEGALOTIS ALTICOLUS Merriam. 



Cerro San Felipe Harvest Mouse. 



(PI. I, fig. 12; PI. IV, fig. 12.) 



Reithrodontomys megalotis alticolus Merriam, Proc. V/ash. Acad. Sci., Ill, 1901, p. 556. 



Type locality. — Cerro San FeUpe, Oaxaca, Mexico (altitude 10,000 

 feet). 



Distribution. — Known only from vicinity of type locahty. 



Characters. — Similar to saturatus; tail shorter; skull with larger 

 bullae and more inflated braincase. 



Color. — Upperparts mixed black and ochraceous-buff, darkest 

 on the dorsal area; ears fuscous, with a blackish patch on lower 

 inner margin; feet huffy white; ankles with a dusky streak; tail hair- 

 brown above, grayish white beneath. 



Slcull. — Similar in size and proportions to that of saturatus; brain- 

 case more inflated (subglobular) ; bullae larger and more inflated; 

 nasals narrowed to a point posteriorly. 



Measurements. — Type ( ad.): Total length, 153; tail vertebrse, 

 75; hind foot, 19. Average of two adults from La Parada, Oaxaca: 

 152; 78.5; 18.5. Skull: (See table, p. 81). 



Remarlcs. — This subspecies is a slightly differentiated form, very 

 closely related to saturatus, from which it differs chiefly in shorter 

 tail and in slight cranial characters. It seems to be confined to the 

 Cerro San FeHpe and its environs. Specimens from La Parada, at 

 the base of the mountain, are not quite typical. 



Specimens examined, — Total number, 3, from the following localities 

 in Mexico : 



Oaxaca: Cerro San Felipe, 1; La Parada, 2. 



1 Collection Field Mus. Nat. Hist. 



