460 BULLETIN 56, UNITED STATES NATIONAL MUSEUM. 



Hist., XXX, No. 1, Dec-. 27, liKll, p. 96 (Syst. Results Study N. Am. Mam. to 



close of 1900). 

 Reithrodontomyslongicauda, Allen, Bull. Am. Mus. Nat. Hist., VI, 1894, p. 320 (in text). 

 [Reithrodontomys] arizonensis , Elliot, Field Col. Mus., Zool. Ser., II, 1901, p. 153 



(Synop. Mam. N. Am.). 



Type-locality. — Rock Creek in the Chiricahua Mountains, Cochise 

 County, Arizona (altitude, 8,000 feet). (Type, skin and skull, in the 

 American Museum of Natural History, New York.) 



Geographical range. — Known only from the type-locality. 



The following is the original description: 



Description. — Adult. — Above brown, lined with black, and washed with reddish fulvous, 

 including the whole top of the head; middle'of back slightly darker than rest of the dorsal 

 surface; fulvous of sides strongly golden, forming a prominent broad lateral line, extend- 

 ing from the cheeks to the tail. Below grayish white, the fur plumbeous at base, with a 

 rust-colored patch on the breast. Ears blackish, particularly along the outer border above; 

 feet soiled white; tail nearly naked, indistinctly bicolor, dusky on the dorsal surface, gray 

 below. 



Young. — Grayish brown above, ashy plumbeous below. Tail sparsely haired, the hairs 

 only partly concealing the annulations. 



Measurements. — Type: Length, 152; tail vertebrae, 78; hind foot, 18; ear, 13; ratio of 

 tail vertebrae to total length, 51.3. Four adults measure: Length, 149 (145-152); tail 

 vertebra, 78 (74-80); hind foot 17 (16-18); ear, 13 (12..5-14). 



This species finds its nearest relative in R. longicauda of California, from which it differs 

 n more reddish coloration, particularly on the head. In size it is also considerably above 

 the average of R. longicauda. Geographically the two forms are widely separated, so far 

 as known R. longicauda not being found east of the San Jacinto Mountains in southern Cali- 

 fornia. (Bull. Am. Mus. Nat. Hist., VII, 1895, p. 134). 



REITHRODONTOMYS MEGALOTIS (Baird). 

 BIG-EARED HARVEST-MOUSE. 



Reithrodon megalotis Baird, Rep. Pacific Railroad Surv., VIII, 1857, p. 451, pi. lxxxiv, 

 fig. 4 (skull); Rep. U. S. and Mex. Bound. Surv., II, Pt. 2, Mam., 1859, p. 43, pi. 

 xlvii, fig. 4 (structural details) ; pi. lxx, fig. 6 (structural details). Between Janos, 

 Chihuahua and San Luis Springs (= Lang's Ranch), Grant County, New Mexico. 



Reithrodontomys megalotis, AllEx\, Bull. Am. Mus. Nat. Hist., VI, 1894, p. 320 (Fairbank, 

 Arizona); VII, p. 234, June 29, 1895 (Fairbank and San Bernardino Rancli, Ari- 

 zona); VII, p. 125, May 21, 1895 (monograph of Reithrodontomys). — Miller and 

 Rehn, Proc. Bost. Soc. Nat. Hist., XXX, No. 1, Dec. 27, 1901, p. 98 (Syst. Results 

 Study N. Am. Mam. to close of 1900). 



[Reithrodontomys] megalotis, Elliot, Field Col. Mus!, Zool. Ser., II,. 1901, p. 151 (Synop. 

 Mam. N. Am.); IV, 1904, p. 259, fig. " 43" (skull), fig. " xli" (animal). (Mam. 

 Mid. Am.). 



Type-locality. — Janos Plain, on wagon road between Janos, Chi- 

 huahua, and San Luis Springs (Monument No. 66), Grant County, New 

 Mexico. (Type, skin and skull, Cat. No. |||f , U. S. National Museum.) 



Geographical range. — Sonoran Zone of the Elevated Central Tract. 

 Dr. J. A. Allen has recorded the capture of this harvest mouse at 

 Silver City, New Mexico; at Fairbank, Fort Huachuca, and St. 

 Thomas, Arizona, and at other places not far from the Mexican Line. 

 Found it as far east as Monument No. 15. 



