Coenobita perlatus, from this island. Collections were made at approxi- mately daily intervals commencing with the third day following the Nectar test until the ninth day and thereafter at lengthened intervals until approximately monthly intervals. years after the test. Sampling continued until about two Strontium-89 and -S0 were detected in the exoskeletons and other parts of the crab. The amount in the exoskeletons remained at a nearly constant level, excepting nuclear decay. Levels of activity, three days after the Nectar test were a high of 5 million d/min-g in the gut, but at the end of the two years were typically about 10 thousand d/min+g (Held, 1960). . i j The first large-scale land-based study of residual radioactivity wag in 1964 by the Laboratory of Radiation Biology of the University of Waouaiglou. The study was at Daiwelok, Bikini, aad Rougelap Atolls. This was eight years after the last test in this area of the world, and so allowed observation of long-term effects of nuclear detonations (Welander et al, 1966). Hundreds of specimens of a broad range of organisms were collected for radioanalyses and later evaluation at the University. BEST AVAILABLE COPY External radioactivity was measured by beta~gamma survey meters at three feet above ground level. Following are some of the observations: External Radiation in mR/hr Island Average Runit (Yvonne) Rigili (Leroy) Bogombogo (Belle) Engebi (Janet) ., Maximum 0.13 0.04 9.80 1.0 (Near craters at north) . 0.23 0.22 0.70 22 al