10> F | “4 wal | 4 ® PLATE 5953 _ c/m/ SAMPLE OO PLATE 15306 Qa A @ © pLATE 5520 ek t 10 3 bo Fig. 4. l 100 200 300 DAYS AFTER L 400 MAY 14, 500 1954 l 600 1 700 Decay of beta-activity in three Coenobita carapace samples, each compared with the theoretical decay curve ( solid lines ) for 5r89 + Sr9° from Figures 2 and 3. -2T- 10