



Centimeters 



Figure 18. — Four shapes of beaks on left valves of old oysters, C. virginica. 1 — narrow, short and almost straight; 

 2 — strongly curved to the posterior; 3 — of medium width, pointed forward; 4 — very broad and slightly curved to the 

 posterior. 



from figure 22, the sliells are almost identical in 

 shape and size. 



Oysters are frequently marketed under specific 

 brands or trade names such as Blue Points (fig. 

 15), Cotuits, Chincoteagues, and others which 



imply the existence of local varieties different 

 in size and shape of shells. There is no e\adence, 

 liowever, to substantiate this claim. So-called 

 "Blue Points" characterized by round shape, 

 strong shell, and medium size may be found. 



MORPHOLOGY AND STRUCTURE OF SHELL 



19 



