LIDICKER 1958 (July 26 cont.) Casa Blanca (17 mi. S Casa Blanca) we picked up a large blue striped colubrid DOR. 1/2 mi. further we saw a rock squirrel. 12.9 mi S Casa Blanca Larrea opened & was almost solid in patches. 1.2 mi. further we noticed our first saguaro. 6.4 mi. S Casa Blanca - no longer any Larrea but instead the habitat is very open with scattered low mesquite & some short grass. Saw an oriole here which seemed to be a Bullock's. 2.3 mi. N of Casa Blanca is Estacion Llano. Just N of here there is a thick stand of Larrea - then back to open scrub again. About 8.3 mi. S Santa Ana there is much Larrea & some jalo verde. 7 mi further the desert gets more gravelly with a few saguaros, but still much Larrea & cholla. To 11.2 mi. from Santa Ana to Magdalena. (in this stretch) Here, the slopes along the Magdalena Valley are very gravelly & not good dips habitat. There may be a few good areas in the uncultivated parts of the valley. Even the flat areas are quite gravelly & soil seems darker. There is no obvious change in the vegetation. The whole area around Magdalena is hilly with medium dark gravelly soil. Later it becomes fairly open with jalo soil, but is still hilly, moderately gravelly & with some grass. We stopped in Nogales for little over an hour to take a look at the turista shops. Then we went through customs & into the U.S. This was about 1230. We continued N on