A semiquantitative analysis of a Messerschmidia sample collected in 1956 at Wotho Atoll was made in a single-channel, 50-position, automatic advance gamma spectrometer with a two- inch well-type sodium iodide crystal. Por some of the 1958 samples the amount of sr9° was Getermined by the precipitation plus ion-exchange method of Kawabata and Held (1958). Radioactive beta decay data were obtained for some of the 1956 samples. The and common names of the organisms are used in the text tables, The scientific mames are given in Appendix Table M. RESULTS Gross Beta Radioactivity The individual gross beta values plus or minus the 95 per cent counting error from ten collection sites during the interval 1954 to 1958 are given in Appendix Tables He ARCHIVE A value identified as background signifies that the counting error was as great or greater than the net count, count after background was subtracted. appendix tables and liver, for algae, The i.e., data from coconut meat and milk, the the fish muscle and sea cucumber muscle are summarized in Table 2. o