CHAPTER XVI 



THE JOINTED-FOOT ANIMALS: ARTHROPODA 



The Shelly Crawlers each returning year 



Cast off their shells and new-made Armour wear. 



Oppian, Halieutica 



The Allies of the Crayfish : Crustacea 



The Lobster. Except for the considerable difference in 

 size, and the slight differences in the shape of the body, 

 the number of gills, and the structure of abdominal append- 

 ages, the description of the adult crayfish would serve for 

 an account of the structure of our common species of Ameri- 

 can lobster, Hom'arus america'nus. The lobster is found in 

 greatest numbers along the coast of Maine and of the Ca- 

 nadian maritime provinces. Toward the south the number 

 gradually decreases to the Delaware breakwater, beyond 

 which they are very rare. In their days of greatest abun- 

 dance they grew to be about sixty centimeters (two feet) in 

 length, weighing twenty-five pounds, but with the increase 

 in the activity of the lobster-fishing industry they are now 

 rarely to be found weighing over two pounds. 



The lobster lives on the bottom. It is protectively col- 

 ored, but it does not depend wholly upon that condition 

 for escaping the notice of its enemies. In shallow waters 

 lobsters are known to conceal themselves beneath masses 

 of brown seaweed in pits and holes, and also to find safe 

 retreat beneath jutting ledges of rock, where they rest with 

 the abdomen doubled beneath, ready to dart out and seize 

 passing prey in their claws. We have no way of knowing 

 the exact habits of the animal when at its greatest depth 



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