MAMMALS OF THE MEXICAN BOUNDARY. 385 



Peromyscus leucopus sonoriensis, Allen, Bull. Am. Mus. Nat. Hist., VII, p. 229, 



June 29, 1895 (in small part). 

 [Peromyscus texanus] sonoriensis, Mearns, Proc. II. S. Nat. Mus., XVIII, 1S96, p. 446. 

 [Peromyscus americanus] sonoriensis, Elliot, Field Col. Mus., Zool. Ser., II, 1901, 



p. 125 (Synop. Mam. N. Am.). 

 Peromyscus texanus sonoriensis. Miller and REHN,Proc. Bost. Soc. Nat. His., XXX, 



No. 1, Dec. 27, 1901, p. 86 (Syst. Results Study N. Am. Mam. to close of 1900). 

 [Peromyscus] leucopus sonoriensis, Elliot, Field Col. Mus., Zool. Ser., IV, 1904, p. 181 



(Mam. Mid. Am.). 



Type-locality. — Santa Cruz, an old Mexican town, on the Santa Cruz 

 River, in Sonora, about 6 miles south of Monument No. Ill, Mexican 

 Boundary Line. (Type, skin and broken skull, Cat. No. i\S%, U. S. 

 National Museum.) 



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

 Along the waters of the Gila River and its tributaries. Le Conte, in 

 his original description of this race, states ° that it was "collected by the 

 Boundary Commission, under Major Graham;" and Professor Baird 



a be 



Fig. 70. -Peromyscus sonoriensis. a, dorsal view of skull; b, crowns of lower molars; 



C, CROWNS of upper MOLARS. 



tells us^ it was "characterized as H. sonoriensis by Major LeConte 

 from specimen 146 of the Smithsonian collection." The skin and 

 skull of this specimen, labeled ^' Hesperomys sonoriensis" in \vh.a,t is 

 supposed to be Le Conte's handwriting, which is undoubtedly the type 

 of Hesperomys sonoriensis Le Conte, and has always been so consid- 

 ered, are now before me. I have compared this type with topotypes 

 which I collected at the town of Santa Cruz and at other places on 

 the Santa Cruz River in Arizona and Sonora, and find them to be the 

 same — the animal described below. 



Description. — Selecting from an abundance of material a fine adult 

 male, in winter pelage (No. flsio; U.S.N.M., coll. International 

 Boundary Commission) , collected by F. X. Holzner, at Lochiel, Arizona, 

 on the Santa Cruz River, a few miles north of the type-locality, Decem- 

 ber 5, 1892, it is seen to be larger and darker in color, with larger ears 

 than the P. s. blandus of the Eastern Desert Tract. The upper sur- 



aProc. Acad. Nat. Sci., Phila., VI, 1&53, p. 413. bMam N. Am., 1857, p. 475. 

 30639— No. 56—07 m 25 



