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FIRST BOOK OF ZOOLOGY. 



121. Just below the eyes are two long, and two short and 

 double antennae, or feelers, and directly below these are six 

 pairs of variously shaped and jointed appendages closely 

 packed together. They surround the mouth and assist in 

 securing and preparing the food for the stomach. The first 

 pair are called jaws, or mandibles, and are furnished with 

 sharp cutting edges for biting the food, and a flattened sur- 

 face for grinding or crushing it. The next two pairs are 

 called maxillae, and are accessory jaws. The pair of mandi- 

 bles and the two pairs of, maxillse, with another pair just 

 behind, making four pairs in all, belong to the head, the 

 other tw^o pairs of mouth-parts belong to the thorax, and are 

 so evidently modified claws or feet that they, with the pair 

 just in front of them, are called foot-jaws or maxillijjedes. 

 {See Fig. 126, in which these parts are all named.) 



122. From the under side of the body project five pairs 

 of jointed legs, and these differ in shape and size. The first 

 pair are much larger than the rest, and in the lobster are 



Fig. 123. — A Big Claw of the Lobstek, showing tiik Wood::n Wedge, a. 



called the hig elaivs. They carry at their extremities big 

 pincer-like jaws capable of giving a sharp nip, and which 

 are used as weapons of defense, and also to hold on to their 

 prey. The lobster can bite very severely with these big 



