1914.] 



EEITHEODONTOMYS EUFESCENS GEOUP. 



57 



heavily washed with pinkish cirmamon. Worn pelage (July specimens, 

 Jico, Vera Cruz) : Underparts somewhat paler; ears and tail blacker. 



Shull, — Larger than that of B. fulvescens difficilis, with longer and 

 relatively slenderer rostrum; braincase usually subglobular (occasion- 

 aUy moderately flattened) ; nasals long and narrowed posteriorly to a 

 point, ending about on a line with premaxillse; zygomata moderately 

 contracted anteriorly; audital bull^ relatively small; palatal foramina 

 long, reaching to or beyond plane of first molars. Enamel pattern of 

 upper molars in some specimens simple, in others showing incomplete 

 subsidiary loops and small accessory tubercles. 



Measurements. — Average of 10 adults from Jico and Jalapa, Vera 

 Cruz: Total length, 176 (168-182); tail vertebrae, 98 (93-104); hind 

 foot, 20 (18-21). Skull: (See table, p. 81). 



Remarlcs. — ^This subspecies is one of the darkest forms in the genus. 

 It has a rather limited range in the humid mountainous parts of 

 eastern Mexico, intergrading with luteolus in Oaxaca and Guerrero. 

 Its range overlaps slightly that of fulvescens difficilis (both species 

 occurring at Jalapa, Vera Cruz), but it does not intergrade with any 

 member of the fulvescens group. It is readily distinguished from 

 them by its dark tawny coloration and unicolor tail. 



In dental characters this species is quite inconstant, as pointed out 

 above; it is considered an aberrant member of the subgenus 

 Reithrodontomys, bridging the gap between it and Aporodon in much 

 the same way that levipes does. 



Specimens examined. — Total number, 15, from the following locali- 

 ties in Mexico : 



Vera Cruz: Jalapa, 10;^ Jico, 8. 

 Puebla: Huauchinango, 3. 

 Queretaro: Pinal de Amoles, 1. 

 Oaxaca: Reyes, 1. 



REITHRODONTOMYS RUFESCENS LUTEOLUS subsp. nov. 



Yellow Harvest Mouse. 



(PI. II, fig. 6; PI. V, fig. 6.) 



Type from Juquila, Oaxaca, Mexico (altitude 5,000 feet). No. 

 71558, U. S. Nat. Mus., Biological Survey Collection, $ adult, Feb. 28, 

 1895; E. W. Nelson and E. A. Goldman. Original No. 7579. 



Distribution. — Mountains of Oaxaca and Guerrero. 



Characters. — Similar to rufescens but colors brighter and less 

 blackish; ears larger and tail longer; skull with flattened braincase; 

 molars without accessory cusps. 



Color. — ^Upperparts and sides rich ochraceous-buff, varying to 

 pinkish cinnamon, more or less darkened on the back with blackish 



1 Collection Am. Mus. Nat. Hist. 



