Greene, H. 1982 22 March What a walkin' day! Left at 0830 w/ Manuel Santana and Jay Savage - Walked Far Jory Trail to Hartshorn to Southwest Trail to West Boundary Trail to Near Research Trail and back in to Station. Found a gravid ♀ (2 eggs) Rhadinæa decorata crawling in sun/shade on leaves on trail at 0948 hr, 770m on S W Trail. On West Boundary Trail saw and photographed what we thought were Black Chachalacas but are evidently Crested Guans. Found a Coniophanes fissidens crawling on trail at 1126hr on the Near Research Trail at 150m. Just before lunch Edwin Paniagua, the Station guard, reported seeing a Lachesis muta on the Central Trail near the Old South Boundary. At 1300 hr we (Edwin, Manuel, me) walked to ≈1850m on this trail and then ≈10m in to the forest in a low, swampy place. The snake was exposed on dark soil behind (≈1.5m) a large, old fallen tree. There were scattered short plants but little leaf litter. Evidently a female - short tail and Edwin says males are smaller - and certainly over 2 m long. She lay in a loose coil w/ head on body, motionless while I took many photos. When we finally touched her w/ a probe she tongue-flicked and finally crawled slowly away into a thicket. Never struck or made any movement,