The Moon Snail 45 



be collected by the hundreds. But to get specimens of 

 the living aninial is quite another matter. Burrowing 

 in the sand to the depth of two or more feet, where 

 they remain hidden most of the time, they are seldom 

 seen. Yet even where one can be observed incautionsly 

 projecting from its burrow, it is not so readily cap- 

 tured. At the slightest jarring of the sand in its neigh- 

 borhood, It takes alarm and Immediately disappears. 

 And it requires a rapid and skillful digger with a spade 

 to catch up with it. Its quick descent In the sand is 

 accomplished by means of Its remarkable foot. This it 

 extends downward Into a point; then expanding the tip, 

 the organ becomes wedged in the sand, enabling the 

 animal to draw close the shell; and by this perform- 

 ance, quickly repeated, the razor clam makes a speedy 

 retreat. Now sometimes the razor clam likes to take a 

 swim. Here, too, the efficiency of its foot is displayed. 

 With a flick of this organ the animal pulls itself spas- 

 modically but swiftly through the water. 



Although all bivalves are pelecypods, not all uni- 

 valves are gastropods. (The word "gastropod" means 

 "stomach foot.") Only two mollusks, however, are 

 exceptions to this statement. These are the tooth 

 shells, or Dentalia, and Nautilus, which belongs to 

 those divisions known as the scaphopods and cephala- 

 pods, respectively. So In the strict sense of the word 

 the term "univalve" has its limitations, but as It has 

 come into such common use in reference to the gastro- 

 pods, its employment is now generally restricted to 

 these mollusks. 



Now I have been so lavish with strange names and 

 scientific terms that the reader Is apt to have become 



