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 determined 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 names are given in Appendix Table M. RESULTS Gross sacra Ene) Department of 1G ian’ vity oacti Beta Radi j 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 A to K. 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 for algae, and liver, The data from coconut meat and milk, and sea cucumber muscle i.e., the the fish muscle are summarized in Table 2.