R. Zweifel 1953 Journal En route north from Mazatlan, Sinaloa the canopy. July 18 We left Mazatlan at 8:30 AM, heading north along the main highway 0.0 mi. Mazatlan (Pat Office) 11.7 mi. Stopped to look for bats in palm trees. Found more - fronde (skirts) too sparse. Shot two Holbrookia maculata and Scleronyx clarki, the scelop on the trunk of a palm tree. 40.6 mi. Rio Piasla 48.9 52.8 mi. Rio Elota 74.0 mi. Lunch stop. Collected Cremidophorus sacki, Holbrookia maculata and Scleronyx clarki. The cremils are the colorful spotted form. Thorn forest. 136.6 Culiacan 166.1 End of pavement 166.5 Penico 228.9 Guamuchil 238.0 Camp for the evening. I walked the dirt roads by our campsite in the evening and found three Bufo mazatlanensis and a Bufo alvarius. The latter has not been recorded from Sinaloa previously. Also taken here were Uroanura ornatus and Cremidophorus sacki, the spotted, brightly colored type.