1914.] 



EEITHRODONTOMYS FULVESCENS GEOUP. 



51 



Specimens examined. — Total number, 36, from the following local- 

 ities in Mexico : 



Vera Cruz: Maltrata, 1; Orizaba, 18; Mirador, 2; Jalapa, 14.^ 

 Puebla: Tehuacan, 1. 



REITHRODONTOMYS FULVESCENS TOLTECUS Merriam. 

 ToLTEC Harvest Mouse. 

 (PI. II, fig. 10; PI. V, fig. 10.) 



Reithrodontomys levipes toltecus Merriam, Proc. Wash. Acad. Sci., Ill, 1901, p. 555. 

 Rhithrodontomys inexspectatus Elliot, Field Columb. Mus., Zool. Ser., Ill, 1903, p. 

 145 (Patzcuaro, Michoacan). 



Type locality. — Tlalpam, Federal District, Mexico. 



Distribution. — Table-land region of southern Mexico, from southern 

 San Luis Potosi to Mchoacan and the Valley of Mexico. 



Characters. — Similar to tenuis, but decidedly larger and slightly 

 darker. 



Color. — ^Upperparts mixed black and rich ochraceous-buff, with a 

 cinnamon tinge, the black usually showing a tendency to form a median 

 band on the back from nose to tail; sides pure ochraceous-buff or 

 sparingly mixed with black; underparts with a slight tinge of pale 

 buff; tail fuscous or hair-brown above, grayish white below. 



SlcuU. — Similar m shape to that of tenuis but decidedly larger; 

 braincase somewhat more inflated, and evenly rounded; rostrum 

 long and relatively slender; zygomata nearly parallel to axis of skull. 



Measurements. — ^Average of 2 adults from type locaJitj^: Total 

 length, 193 (189-196); tail vertebra, 106 (104-108); liind foot, 21.5 

 (21-22). One adult from Patzcuaro, Mchoacan: ISO; 105; 21. 

 Average of 2 adults from Kio Verde, San Luis Potosi: 192; 110; 

 21.8. Skull: (See table, p. 81). 



ReTYiarTcs. — This is a well-marked form of the fulvescens group ^ 

 occupying the higher parts of the Mexican table-land. It is poorly 

 represented in the material at hand, and its characters and exact 

 distribution are not well known. SkuUs from the same or near-by 

 localities show an unusual amount of variation in size. 



Intergradation apparently takes place between toltecus and tenuis 

 and between toltecus and Jielvolus, but the material at hand is 

 too scanty to show this clearly. Specimens from Eio Verde, San 

 Luis Potosi, and from Zamora and Los Reyes, Michoacan, are con- 

 sidered intermediates between this form and tenuis, and specimens 

 from Huajuapam, Oaxaca, and Chilpancingo, Guerrero, interme- 

 diates between it and Jielvolus. The series from Los Reyes is very 

 puzzling. In color the specimens are all exactly alike, being a little 

 darker and redder than either tenuis or typical toltecus. One speci- 



1 Collection Am. Mus, Nat. Hist, 



