JESimpson,1938 Peromyscus crinitus 850±ft, Paso McDougal, Pinacate Region, Sonora March 25,1938 In mazonite and granite rocks on east face of Sierra Hornaday caught 2; σ771,♀75. 1100±ft, Crater Elegante, 34 mi. w. Sonota, Sonora. March 29,1938 In grey rock and cinders on rim of crater σ790 taken among creosote and ochotillo. Inside rim in large rocks among creosote, cholla, and some ochotillo σ791 taken; the latter mouse was of much lighter pelage than those taken in this area. On east face of red-lava hill just s. of crater rim among cholla [sparse] and ochotillo 2 dark mice taken (σ792,♀93). 50±ft, Cerro La Cholla, 6 mi. wnw Punta Peñasca, Sonora. April 3,1938. σ7111 taken in granite hills near bay of Gulf among creosote, ocotillo, and cholla. April 4,1938 σ7117 among creosote, cholla, and ocotilla along bank of wash thru granite hills.