92 



DEPARTMENT OF THE NAVAL SERVICE 



where the entire surface of the scale is abnormal and no winter rings are to be seen. 

 Plate V, figs. 1.5 and 16 give photographic reproductions of the central portions in a 



Plate VI. 





'/v/- _..<. 





-::■'■ «^^- 







n 





normal and an abnormal scale from the same fish. Ihe occurrence of these abnormal 

 scales is highly irregular; on one specimen, numbers may be found, while in another, 

 long and carrfnl search will be required to discover a single one. It is furtlier remark- 



