-~10- Table 1. Total B-activity and Sr20+. ¥99 in Coenobita Carapace Determinations made in January and February, 1956. Averages of three samples and their standard errors are given. Date collected Jan.-Feb., 1956 d/m/g wet $r904 ¥90 activity Feb. 1956 d/m/g wet 4/15/54 6900 t 672 THSk + 952 5/26/54 10243 t 968 9763 t 975 8/19/54 14851 41413 15568 +1237 10/5/54 4362 + 431 4043 t 385 3/15/55 10368 ¢ 581 11281 ft 479 2/9/55 12516 +1594 12532 t 1484* 8/12/54 or * Total B-activity Average of duplicate aliquots of three pooled samples as determined by Dorothy J. South, Applied Ftrsheries Laboratory. na