900±ft, ½ m.s. Crater Elegante, 34 mi.w. Sonora, Sonora March 28,1938 In the second-night stand of the 50 mousetraps caught only one P eremicus and two N albigula (o787) along the rocky-bank of the wash; nine of the traps were sprung and empty. In the 50 live-traps set in a small wash thru the lava fields caught one ♀P eremicus which was subsequently turned loose; it ran in a more or less straight line over the lava field away from our camp and also its home ground. Put up one of the wood-rats and the Rufous Hummingbird (o788) shot last night. Helped Dr. Benson put up Señor Deladillo's specimens as the latter went out to set gopher-traps. Set out trap-line at: 1100±ft, Crater Elegante, 34 mi.w. Sonora, Sonora. Some of the traps on the outside of the rim, some on top of the rim, about half inside the crater's rim, 50 mouse - and the balance on the west face, top, and east face of a brick-red lava-rock hill just at the south rim of the crater. (The wind has blown very strongly all day since dawn.) March 29,1938 Caught nothing outside the rim of the crater but on top of the rim in similar gray rock-and-cinder, ochotillo-and-creosote habitat caught 1 Prognathus baileyi (o789; cheek-pouch contents saved. gray noctub and 3 Peromyscus eremicus(o789) and 1 Peromyscus crinitus (o790); inside the rim of the crater in the large rocks caught 1 P. crinitus (o791; the pelage of this one