1914.] 



EEITHEODONTOMYS FULVESCENS GROUP. 



55 



Remarlcs. — This subspecies is most nearly related to Tielvolus, dif- 

 fering from it in much deeper coloration. It resemples R. lempes 

 rather closely in external appearance, but differs widely from itia 

 skull characters. A specimen from Chilpancingo, Guerrero, has a 

 longer skull than the type, somewhat suggestbrig the skull of toltecus. 



Specimens examined. — Total number, 4, from the following locali- 

 ties in Mexico : 



Oaxaca: Llano Grande, 2. 



Guerrero: Acapulco, 1; Chilpancingo, 1. 



REITHRODONTOJ^IYS AMCENUS Elliot. 

 Tehuantepec Harvest Mouse. 

 (PI. II, fig. 1; PI. V, fig. 1.) 

 RTiithrodontomys arrwenus Elliot, Proc. Biol. Soc. Wash., XVIII, 1905, p. 234. 



Type locality. — Eeforma, Oaxaca, Mexico. 



Distrihution. — Known only from the t3rpe locahty. 



CTiaracters. — Size very small; tail moderate; similar in color to 

 R.f. tielvolus but upperparts deeper ocliraceous. 



Color. — Upperparts bright ochraceous-buff, becoming tawny-ochra- 

 ceous on middle of the back, where indistinctly lined with black; 

 underparts and feet white; tail hair-brown above, paler below. 



Slcull. — Small, with short heavy rostrum; braincase moderately flat 

 and narrowed posteriorly; zygomata sUghtly contracted anteriorly; 

 bullae small and flat; interpterygoid fossa very broad ; palatal foramina 

 long, reachhig behind plane of molars. 



Measurements. — Type: Total length, 141; tail vertebrae, 81; hhid 

 foot, 18.5. Skull: (See table, p. 81). 



Remarlcs. — This species, known from only a single specimen, seems 

 not to be closely related to any of the recognized forms. It most 

 nearly resembles R. f. Jielvolus in color, but differs widely from it in 

 size and cranial characters, being decidedly smaller than any other 

 species in southern Mexico. It inhabits the low coast plain bor- 

 dering the GuK of Tehuantepec in southern Oaxaca. 



Specimen examined. — One, the type. 



REITHRODONTOMYS OTUS Merriam. 



BiG-EAEED Harvest Mouse. 



(PL II, fig. 2; PI. V, fig. 2.) 



Rdthrodontomys levipes otus Merriam, Proc. Wash. Acad. Sci., Ill, 1901, p. 555. 



Type locality. — Sierra Nevada de CoHma, Jalisco, Mexico (altitude 

 6,500 feet). 



Distribution. — Kiiown only from the type locality. 

 Characters. — Similar to R.f. toltecus, but tail longer and ears larger; 

 colors more ochraceous and less blackish. 



