PETERSON ET AL.: MARK-REOAPTIRE TEST OF HARD CLAMS 



B 



D 



FIGURE 3. — A photographic illustration of a representative sectioned clam shell from each of the four collection dates (A-D: dates given in 

 Figure 2 legend) in the mark-recapture test of whether Mercenaria mercenaria from Cape Lookout, N.C., deposits annual growth bands. Lines 

 drawn on the outer surface of each clam shell represent the sizes at each measuring date: 21-22 June 1978; 20 September 1978; 21 April 1979; 

 17 October 1979; and 22 May 1980. Clam A lacks surface lines for the last two dates because it was collected on 17 October 1979, whereas clam 

 B, collected on 22 May 1980, lacks the last surface line. The annual bands are visible as dark bands in the middle and outer layers in the cross- 

 sectional cuts through each shell. 



771 



