Greer, H. 1989 July 11 (continued) that a visitor found on a cement path in the lab clearing at approx 1200 hr noon (122+31m, 1-2g), just before lunch Dave and Andell and I used a receiver to locate the Lachesis muta now coiled under a small plant and a few meters in shade (from where we released her. I walked very near before locating her visually, yet she simply remained immobile w/ head up. At 1310hr Andell found an adult Scaphiodontophis venustissimus (4/5+ 125+? mm, 43.5g, ?) crawling across a cement path at the edge of the lab clearing in forest shade. Response to handling was rapid erratic crawling, w/ jerking of the incomplete tail. No musks or biting. At 2145 hr we found the Lachesis muta still under the plant, after we had walked out to CES 700 m -- caught only an Eleutherodactylus fitzingeri (8g) in litter on the Sendero Siera. July 12 Rained all night. At 0604 hr found the Lachesis muta under the plant, and again at approx 1045 hr. In between we walked approx 200 m out into the forest at CES 500 looking unsuccessfully for Lachesis. At 1310 hr a workman showed me a small, brightly colored Micrurus nigricinctus under a tractor wheel (4.0g, 265+25), w/ Dave and Andell, walked out CCC to Camino Central, via El Suampo to Sendero Holdridge and back in. Found a cat scat, evidently containing Tayassu, at CCC 220. At approx 1930 hr Billie Hardy