44 WEST COAST SHELLS 



valves, some white, some yellow, and some red, while 

 the right valves have about twelve serrated ribs and 

 are apt to be mottled in color. When the shell is 

 about an inch long a reddish purple spot begins to 

 show along the hinge area, inside the valves. The 

 spot increases with age, and never fades, though the 

 shell may be sadly worn and broken. Fragments 

 of shell on the beach show the color distinctly. At 

 the same time the little creature quits its free life and 

 settles down in some quiet nook, like the inside of 

 an old abalone-shell. There it turns over on its left 

 side and begins to grow, fastening itself firmly to 

 the nook that it has chosen. 



And now, as it is confined, it loses its perfect sym- 

 metry and grows in whatever direction it has room, 

 sending out short spines and thorns for defense. 

 Sometimes it becomes a giant indeed, with thick 

 shells four or five inches long; but more often it is 

 considerably smaller. The ligament is internal, 

 lodged in a deep, narrow pit; the central muscle-scar 

 is smooth and very large. Live specimens are not 

 common, but dead shells are thrown up all along our 

 coast. Figure 23 shows the appearance of a long 

 and narrow specimen. 



At this point we will quote, for our younger 

 readers, a part of "The Story of the Pecten" from 

 the author's "Shells and Sea-Life." 



THE STORY OF THE PECTEN 



"One bright morning in springtime I found myself 

 swimming with a number of my brothers and sisters 

 in a little pool which had been left among the rocks 



