Plate XLII. 



Monograph- U YSTER-I,YD USTR Y. 



Fi". 67. 



Figures of the egg of the oyster and the yonn*;; oyster in progressive stages of growtli. illustrating the studies of Dr. W. K. Brooks. 



[From the report of T. B. Ferfruson. commissioner of fisht-riea for Maryland.! 



