102 MOLLUSKS 



is one reason for the laws regulating the disposal of sewage, 

 and for government inspection of the feeding grounds. 



SUMMARY 



The parts of mollusks are not arranged in segments 

 like the earthworms or crustaceans. The usual presence 

 of a shell and mantle and the fact that the soft body is 

 not divided into segments helps to distinguish a mollusk 

 from any other animal. The microscopic food of the 

 clam is caught in the mucus and carried by cilia to the 

 mouth. The clams and oysters are valuable for food but 

 should not be eaten if taken from water contaminated by 

 disease germs. Mollusk beds should be protected from 

 such contamination. 



QUESTIONS 



What are some of the common mollusks ? Where do they live ? 

 How do they get their food ? What ones are used for food by man ? 



REFERENCES 



Brooks, The Oyster. 

 Cambridge Natural History, Vol. III. 

 Kellogg, The Shellfish Industries. 

 Linville and Kelly, Zoology. 



