July 145-149 Thamnophis cyrtopsis all from the tributary with water that fed the larger stream bed. Others seen there were not collected. 150-152 Cnemidophorus sonorae: one collected by Philip and other two by John. Went back into El Coyote Ranch and then took the road east to Nacorí Chico. At a point 1.9 miles north of Bacadehuachi got two Crotaphytus collaris (♂+♀). Both were on boulders on the west side of the road. Partly overcast. See back for color notes. Continued on the Naco de Chico road to a point 13.9 miles S.E. Bacadehuachi (by road) where we had to stop because of high water in the first big arroyo on the road after coming down out the mountains east of Bacadehuachi. This point is also approximately 4.1 miles N.W. of Nacorí Chico, Sonora. This locality is the upper west side of a large valley that drains south where Río Yaqui. The vegetation is rather dense thorn scrub with a good deal of Opuntia. John and Jim say that the vegetation has a decidedly southern aspect which I can see in the great lushness and density of the vegetation. We arrived between thunder showers and