The Scallops 



343 



detrimental and useful to the scallops, detrimental be- 

 cause their mass checks the food-bearing currents, and 

 useful because they undoubtedly offer great protection 

 by preventing the washing away of these light bodies in 



FIG. 67. Pecten one-half inch in diameter, a m, adductor 

 muscle; b, byssus; c, eye on mantle edge; /, foot; g, gill; h, 

 heart; /, shell ligament; m, mantle; mf, mantle fold; p, 

 striated inner surfaces of the palps. 



storms. Pectens that have had only scanty protection 

 of this kind are often thrown up by waves to die on 

 beaches. This probably is the explanation of the fact 

 that the best scalloping grounds are on eel-grass covered 

 bottoms. They also attach in deeper water, though in 

 smaller numbers, to stones, shells, and other bodies. 

 Long after they have passed the embryonic stage, they 



