AGE-DETERMINATION BY MEANS OF THE OVARIAN CORPORA 473 



to age. The curve is similar to the diagonal type of Pearl and Miner (1955) and Deevey (1947), but 

 it represents both natural and fishing mortality. A prominent bump in the curve from 20 to 35 years 

 suggests some bias towards older females in the sample as might be expected in view of the tendency 

 (mentioned above) for older animals to be over-represented in the samples. This is a further warning 



Table 3 1 . Frequency distribution of corpora, and apparent survivors up to an age 

 corresponding to 55 corpora. Area II, 1939-41. 



Totals 2681 3361 



19-2 



