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PRACTICAL ZOOLOGY 



mussel, by the cilia which draw the water loaded with minute 

 particles of animal and vegetable matter into the body through 

 the siphon. The commercial value of the clam is not as great 

 as that of the oyster, but is nevertheless considerable. 



Razor-shell Clam. — The razor-shell clam (Fig. 87, B) also 

 lives in burrows in the sand and obtains its food just as the soft- 

 shell clam does. It is a remarkably rapid digger, being able to 

 burrow down into the sand about as fast as one can follow with 



Fie. 88. — A, hard-shell or little-neck clam. 

 B, scallop shell. (From Arnold.) 



a spade. The shell is long and slender, hence its popular name, 

 razor-shell clam. 



Hard-shell Clam. — The hard-shell clams are very abundant 

 on our eastern coast. One species, Venus mercenaria (Fig. 88, 

 A), is commonly known in hotels and restaurants as the " little- 

 neck " clam. It received its specific name (mercenaria) because 

 the purple patch on the margin of the shell furnished " wam- 

 pum," the money used by the Indians. 



Scallop. — Scallop shells are among the most beautiful of 

 seashells, and are well known to every one who visits the sea- 

 coast (Fig. 88, B). The valves of scallops are rounded and or- 



