Plate XL. 



oMonograph-OrSTER-IMD USTR T. 



Vis. 43. 



Fi.'. 40. 



Fin. 4'^. 



S it. 



FiK. 4ri. 



FiK. 44. 



FiK. 4o 



Fiii. 4i». 



Fig. .-.1. 



Fiff. 5(1. 



FiK. 52. 



Figures i>f thr egg of the oyster and tbe ynuiig oyster iu progressive stages of growth, illuslratiiig the studies of Dr. W. K. Brooks. 



[From tbe report of T. B. Ferguson, foiiimissiimei nf H.sliei ies lor MaryliUiil.] 



