92 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Sek. 



"Hesperomys Gamhellii" (part), Cooper, Amer. Nat., 3^ 

 1869, pp. 473, 476 (Fort Mojave). 



"Hesperomys sonoriensis Lee." (part). Cooper, Proc. Cal. 

 Acad. Sci., 4, 1870, pp. 67, 68 (Range does not so far as 

 known extend north of "Southern Coast Slope"). 



"Hesperomys Boylii? Baird," Cooper, Proc. Cal. Acad. Sci.,. 

 4, 1870, p. 74 (Colorado Valley). 



"Hesperomys Gamheliif Baird," Cooper, Proc. Cal. Acad. 

 Sci., 4, 1870, p. 74 (Colorado Valley). 



Specimens examined. — Five : Nos. 5624, 5625, Univ. Calif. 

 Mus. Vert. Zool. ; Nos. 7183, 7186, 145275, U. S. Nat. Mus. 

 No. 5624: original label missing; skeleton only; Fort Mojave, 

 Feb. 24, 1861, J. G. Cooper. No. 5625 : obverse of label "268 

 Hesperomys sonoriensis? [the "sonoriensis?" pencilled in] 9 

 Mojave R. Camp Cady ^' June 6, '61, J. G. C"; reverse, ten 

 measurements. No. 7183 : original label missing; from two other 

 labels attached we learn that the specimen came from "Califor- 

 nia" ; it is credited to the "Geol. Surv. Cal.," and is said to have 

 been collected by Dr. J. G. Cooper ; it has been variously iden- 

 tified as "Hesperomys" merely, "Hesperomys leucopus," "Hes- 

 peromys leucopusf" "gamheli," and "Peromyscus m. sonorien- 

 sis." No. 7186: obverse of label "90 Hesperomys gambelli 6 

 Ft. Mojave Coldo. R. Feb. 14 '61, J. G. C"; reverse, eleven 

 measurements. No. 145275 : obverse of label "19 Hesperomys 

 gambelii Ft. Mojave, Col'do R. Dec. 24th '60, J. G. C," ; re- 

 verse, ten measurements. 



As usual with Dr. Cooper's material these skins were pre- 

 pared with the skulls inside, the forelegs folded on breast, the 

 hind legs crossed and tied just posterior to body or disposed 

 beneath body; tail not skinned (end nearly broken off in No. 

 7183), extended posteriorly; in several of the specimens the 

 abdominal slit is not sewed up. 



Nos. 7183 and 7186 are bright examples of Peromyscus 

 maniculatus sonoriensis both apparently in full winter pelage. 

 It is not improbable that No. 7183 came from Fort Mojave, as 

 did No. 7186. The other specimens are typical sonoriensis^ 

 presenting no conspicuous peculiarities. 



" Camp Cady: San Bernardino County, Cal., on lower course of Mojave River, 

 about lat. 35°, long. 116° 30', a little south of westof the south end of the sink of 

 the Mojave River (see Whitney's Map of California and Nevada, State -Geological 

 Survey of California, 2nd ed., 1874). Camp Cady is shown on all the maps of this- 

 period which I have examined. 



