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ANNULUS 



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ANNULUS 



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ANNULUS 



ANNULUS 



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Annul us formation in yearling bluegills (A, B, C) and yearling largemouth bass (D, E, F). A. Scale of bluegill, 4.2 inches, showing 

 some mdication of annulus formation; fish caught April 17, 1939; age, about 1 1 months. B. Scale of bluegill, 4.4 inches, showing annulus 

 m only the anterior field; fish caught April 17, 1939; age, about 1 1 months. C. Scale of bluegill, 4.8 inches, showing annulus surrounded 

 by a wide margin of growth; fish caught May 30, 19 39; age, 12 months. D. Scale of largemouth bass, 7.4 inches, without annulus, but 

 shovvmg a change of growth rate during 1938. "Cutting over" may be seen in the posterior field but the "cutting over" on the left side 

 does not correspond with that on the right; fish caught March 18, 1939; age, 10 months. E. Annulus nearly complete on scale of bass 8.8 

 mches; fish caught May 30, 1939; age, 12 months. F. Scale of bass, 6.7 inches, with annulus surrounded by a wide margin of growth; 

 fish caught August 28, 1939; age, 15 months. 



PLATE 4 



