TEN-FUUTEU CRUSTACEANS. 



197 



CENTIPEDES, OR MYRtAPODS. 



These are long and wonn-likc, and divided into very 

 numerous rings or joints ; each joint generally bears 

 two pairs of feet. In the temperate zones they are 



Fig. 343. — American Myriapod, 

 or Galley Worm. 



Fig. 344. — American Earwi 

 or Lithobius. 



only two or three inches long ; tropical species are 

 sometimes a foot long, and their bite is often very 

 poisonous. 



CRUSTACEANS. 



These Arthropods have a crust or shell, the head and 

 thorax often united into one piece ; they live in the 

 water and breathe by gills. Some kinds, however, 

 live upon the land. They feed upon all sorts of animal 

 food, and shed and renew their shells many times. 



Crabs, Lobsters and Shrimps, or Ten-footed 

 Crustaceans. 



Crabs can walk forward, backward, and sidewise. 

 The tail, or hind body, is small, and is doubled under 

 the forward part of the body, where it fits into a groove. 

 The kinds of Crab are very numerous, and some are 

 found on every seacoast. They vary in size from that 

 of a penny to those which, with the legs outspread, 

 cover a space a yard square. Some kinds are very 

 much prized for food ; the one shown in Figure 347 



