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BOYS AND GIRLS IN BIOLOGY. 



als, as soon as yon knew how. Now let ns see if we 

 can find and name the different parts of the lobster. 

 There is no kind of use in attempting to do any thing 

 with it unless you have a real lobster before you to look 

 at while I talk. The crawfish, or crayfish, that lives 

 in creeks and rivers, is made in the same fashion as the 

 lobster, only smaller, so one of these will answer just as 

 well (Fig. 109). One thing is very certain, he has a great 

 many different parts, and these, as a rule, are very un- 

 like each other. First, you see he is covered with a 

 shell, which, like the mussel's and clam's, is his exo- 

 skeleton. This shell is very hard like stone, and it is 

 colored purplish black, with pale spots here and there ; 

 you can hardly tell it from the color of the rocks among 

 which the lobster lives. The lobsters which you see 

 in shops are always dressed in scarlet coats, or shells. 

 When these poor f ellow r s are caught they are plunged 

 alive into boiling water, which turns the black coat red. 

 This outside shell, or exo-skeleton, is made up of a 

 great many different pieces instead of two as the mus- 

 sel's ; but those pieces are shaped and joined in such a 

 way as to make three divisions of the body — a head, a 

 thorax, or breastplate, and an abdomen. The head- 

 piece of the shell is pointed in front, forming the beak 

 (Fig. 109), or frontal spine. Behind this head-piece is 

 a groove, or seam (Fig. 109), where the head joins the 



