CHAPTER XXIII. 



The Cockles — Chama — How To Determine the Spe- 

 cies — Some Nestlers — Saxidomus — The Carpet 

 ShelIv — Chione — Amiantis — Pachydesma — The 

 StandeIvLAS — SEMEI.E— The Wedge-ShelIv— Macom a 



.SECTA. 



THE common Heart-shell or Cockle of this coast 

 has a pleasant history. It was spoken of by Cap- 

 tain Dixon, in 1789, who found it at the mouth of 

 Cook's river, in Alaska, along with mussels and other 

 shells. He quaintly states that "half-a-dozen of 

 them would have afforded a good supper for one per- 



Mart., Car'-di-um cor' 



son." 



Its name is Cardiiim corbis^ 

 bis. A beautiful end view of one of them, fully 

 justifying the name '^ Heart-shell," is given in Fig. 



153. The shells are very 

 full and round, the ribs 

 about thirty in number, 

 slightly scaly. Pallial line 

 entire, edge of shells strong- 

 ly toothed, color whitish or 

 light brown. Portions of 

 large, broken shells may 

 frequently be picked up 

 near the Cliff House in 

 San Francisco. The dia- 

 meter of ordinar}' speci- 

 mens is two or three inches. 

 Liocardmni elatiun^ Sby. , 



