-20- Teble 7. radioassay of liver tissue from reef fish collected at Enibuk Island, Ailinginae Atoll, July 11, 1957 Summary of the lsotope Be ta-gamma Betat d/m/g wet d/m/g wet activity, weight zn©5 786 activity,” weight uc /ke Per cent weight gamma wet ok total beta- activity 357 39.5 Coot 4ag 138 2195 21.6 C058 C60 69 54 20 19 032 024 3.5 2.7 Feo5 Mn 54 516 25 .234 .011 25.9 1.2 Unidentified 111** 211** .050 5.6 334 .902 100.0 sr79 Totals 0 1,988 0 0 * Betat activity for Zn©5 is 2.5 per cent of the total Self-absorption corrections for beta radioactivity. activity in cobalt were made by using standards and spikes in 5 per cent citrate dried on 13-inch plates and counted in the methane gas-flow Nucleometer (Lowman et al., 1957). **unidentified radioactivity was estimated by subtracting the calculated beta activity in Zn Cod, and from the beta activity (314 d/m/g wet weight) counted in the methane gas-flow counter.