- 2h. r 10, 7 SPIDER SNAIL 100 1O00F < S wa 4 be to 4 1OOr = 2 q ~ oO —_ tr 4 Te) OIF 25 L 100 DAYS 600 AFTER Figures 7 (left) and 8 (right). 25 MARCH 1, 1954 4 100 Decline in radioactivity of tissues of giant clam and spider snails from northern islands of Rongeélap Atoll. 600