30 



NORTH AMERICAN FAUNA. 



[No. 36. 



REITHRODONTOMYS MEGALOTIS AZTECUS Allen. 

 Aztec Harvest Mouse. 

 Reithrodontomys aztecus Allen, Bull. Am. Mus. Nat. Hist., V, 1893, p. 79. 

 Type locality. — La Plata, N. Mex. 



Distribution. — Northern New Mexico, northeastern Arizona, south- 

 eastern Utah, and western Colorado, north to Grand Junction and 

 Rifle. 



Characters. — Similar to megalotis but with larger ears and skull. 



Color. — Not appreciably different from that of megalotis; ears some- 

 times with irregular dusky blotches. 



SJcull. — Decidedly larger than that of megalotis. 



Measurements. — Average of 7 adults from La Plata and Aztec, 

 N. Mex., and Noland Ranch, Utah: Total length, 144 (133-155); tail 

 vertebrae, 68 (62-73); hind foot, 18 (17-19); ear from notch, 13.8 

 (12-15.5). Skull (see table, p. 81). 



Remarlcs. — This subspecies does not differ from megalotis in color, 

 but its skull is so much larger that it seems desirable to recognize the 

 race. The ears average larger, also, in the series from the type region. 

 Dr. Allen provided the form with a provisional name many years ago, 

 but later placed it in synonymy. 



This race is connected with megalotis by a complete series of inter- 

 grades from New Mexico and Arizona. The specimens from Datil 

 and Manzano Mountains are too young to be satisfactorily identified, 

 but are provisionally referred to aztecus. 



Specimens examined. — Total number, 143, from the following locali- 

 ties: 



New Mexico: Aztec, 39; Espanola, 8; Farmington, 4; Fruitland, 6; Gallup, 1; 



Guadalupita, 1; La Plata, 32; Las Vegas, 2; Manzano Mountains, 1; Rinco- 



nada, 1; Rio Puerco, 4; Wingate, 2. 

 Arizona: Canyon de Chelly, 1. 



Utah: Bluff City, San Juan River, 4; Noland Ranch, San Juan River, 5. 

 Colorado: Arboles, 1; Ashbaugh's Ranch, Montezuma County, 2; Cortez, 1; 

 Grand Junction, 26; Rifle, 2. 



REITHRODONTOMYS MEGALOTIS DYCHEI Allen. 



Prairie Harvest Mouse. 



(PI. I, fig. 7; PI. IV, fig. 7.) 



Reithrodontomys dychei Allen, Bull. Am. Mus. Nat. Hist., VII, 1895, p. 120. 

 Reithrodontomys dycheinehrascensis Allen, Bull. Am. Mus. Nat. Hist., VII, 1895, p. 122 

 (Kennedy, Nebr.). 



Reithrodontomys griseus Ruthven & Wood, Proc. Iowa Acad. Sci., XIX, 1912, 

 p. 204 (not of Bailey). 1 



Type locality. — Lawrence, Kans. 



I Misidentiflcation of specimen by the present writer. 



