E.V. Miller 1940 31 General Account. which were standing from a recent rain. Some of these toads were 'copulating' in the water. We drove through San Luis Potosi (the city) and north toward Matehuala. May 22 We continued toward Matehuala. At Kilometer 112 on the 'highway' we turned off on a dirt road which led through groves of large yuccas and patches of creosote brush. Previous to turning off the highway we had passed through hilly country, some parts having a scant covering of brush and grass and other parts a heavy growth of large brush, and large cacti of several species. In the afternoon we ran into a little rain and then into muddy roads. We were stuck about 8 mi. [illegible] of Matehuala and after getting out of the mud we camped here. I set out 50 M. specials at about 7 30 to 800 P.M. May 23 Took 1♂, 1♀ Peromyscus eremicus, 5♂ Perognathus penicillatus, 2♀ Perognathus welsoni in my traps. These were set along the edge of an old corn field lined with thick mesquite brush. Soil muddy at present from recent rain. Weather clear today. I collected also a ♀ Berwick Wren this morning. I saw Bufo sp., Sceloporus sp., Boat-tailed Grackle, Mourning Dove, White-winged Dove, Desert Sparrow, Clay-colored + Blue Grosbeak. Sparrows, and Mockingbird. We are in a wide valley, running north and south. Collected also a Cnemidophorus sp.