CLASS-BOOK OF ZOOLOGY. 151 



their claws and legs, if these are bruised or touched with 

 a hot iron. 



§ 657. The principal material from which the new shell 

 is hardened, seems to be the two calcareous concretions 

 found in summer at both sides of its stomach, and com- 

 monly called Crab's Eyes. 



§ 658. Crabs feed on dead bodies, spoiled flesh, and 

 all kinds of worms and insects found in the water. They 

 are a numerous family, including all the different species 

 of Crabs, Lobsters, and Craw-fish. 



§ 659. Many small Crabs are very injurious to Fish, 

 upon which they live like parasites, sucking their blood 

 and killing them. The larger ones are useful as an article 

 of food. 



§ 660. Crabs and Lobsters are very pleasant food in 

 those months in the names of which the letter r does not 

 occur — May, June, July, and August. When boiled 

 they become red ; and the tail of the Lobster becomes 

 curved, if the animal was alive when first put into the 

 boiler ; but if not, it remains straight. 



§ 661. The Horse-shoe Fish, found so often on our 

 sea-coasts, is the largest of all insects, reaching the 

 length of four feet. It is found on the northeastern coast 

 of America, particularly in the Straits of Bahama, and also 

 in the East Indies. 



§ 662. The body of the Horse-shoe Fish has ten pincer- 

 like feet, is very small, and covered with a round shell, 

 at the posterior extremity of which is attached a sting as 

 long as the body. 



§ 663. From the eggs of the Horse-shoe Fish a kind of 

 Caviar, called bocassan, is made in the East Indies. 



§ 664. The Centipede has a crustaceous, cylindrical 

 body, about two inches long, with from ninety to a hun- 

 dred legs on each side ; is of a gray color, lives generally 

 in rich ground, and is injurious to various kinds of vege- 

 tables, but principally to cabbage. 



QUESTIONS ON SECT. XXXIX. 



639. What do you know of insects without wings ? 



640. What Insects belong to this Order ? 



641. On what animals are Lice found? 



