PIERCED SHELLS AXD CHITONS 



245 



jects over the pearly inner layer, and makes the fine 

 red edge, so much prized in perfect specimens. The 

 back is somewhat roughened, and is often overgrown 

 with vegetation. The holes are large, usually three 

 in number, and the muscle-scar is prominent. The 

 shell sometimes grows to a length of nine inches, or 

 more. 



All parts of this mollusk are valuable. The 

 Chinese dry the meat and use it for food, and it must 

 be confessed that the great muscle makes a most 

 delicious soup. The shells are sold by the ton, and 

 are largely exported to Europe, where they are made 

 into buttons or used for various kinds of inlaid work. 

 So persistently have these animals been gathered 

 that they are much more rare than they were a score 

 of 3^ears ago, and laws have been made to protect the 

 species from extinction. 



The Black Aba- 

 lone, H alio lis cra- 

 cherodii^ Leach, 

 is shown in Fig- 

 ure 245. It is 

 smaller and more 

 abundant than 

 the last species. 

 The back is quite 

 smooth, marked 

 only by lines of growth. The spire is very short, 

 the holes five to nine in number, though I have seen 

 a specimen that was without any. The color of the 

 outside is greenish-black, while the inside is beauti- 

 fully iridescent, without inclining to any definite 



Fig. 245 



