CHAPTER II 



MUSSELS AND PECTENS 



The great family of the Mussels have elongated, 

 dark-colored shells, and most of them spin a byssus 

 of strong threads by which they anchor themselves 

 to a place of safety. Where the waves dash over the 

 rocks and the white foam curls like flowing milk, 

 there the mussels love to make their home. Moored 

 by their strong cables they enjoy the rush of air and 

 water and fear no danger. 



The principal species on our coast is named 



Mytilus calif ornia?2us, Conr., the 

 California Mussel. A very good 

 picture of an empty shell is 

 given in Figure 15. This spe- 

 cies can be easily distinguished 

 from other mussels by its con- 

 spicuous ribs, which are never 

 wholly absent, particularly on 

 the newest parts of the shell. 

 The beaks of old specimens are 

 apt to be much eroded, but the 

 growing edge is j^rotected by a 

 glossy epidermis. The general 

 color of the shell is purple, 

 though the thicker parts of it 

 are white, and sometimes there 

 Fig. 15. X I are streaks of brown, which har- 



