MYRIAPODA 



111 



on worms. The body has a chitinous covering. The cephalo- 

 thorax is arched and bears the large compound eyes and two 

 simple eyes. The abdomen is almost hexagonal and ends in a 

 long caudal spine. On the ventral side of the cephalothorax 

 are six pairs of appendages, used for securing food and for 

 locomotion. The last pair, the operculum, is broad and leaf- 

 .like and covers the five pairs of leaf-like branchial appendages 

 of the abdomen. These appendages are for respiration. The 

 shape of the body, its hard covering, marginal spines, and its 

 color, which harmonizes with its environment, afford it ample 

 protection and defense. 



There are several other orders, but these will suffice for our 

 purpose in the present work. 



CLASS m. MYRIAP'ODA 



The name indicates myriad footed, hence the common name, 

 thousand-legs. A myriapod is a worm-like tracheate arthropod 

 with a distinct head, a round or flattened 

 body composed of many similar segments, 

 to each of which is attached one or two pairs 

 of appendages. Myriapods have one pair 

 of mandibles, one pair of antennae, and 

 numerous ocelli. " A few species are injur- 

 ious to agriculture, while others are to be 

 classed among our friends." 



Order I. Chilop'oda. — These are myria- 

 pods with the body flattened, with fifteen 

 to one hundred and seventy or more seg- 

 ments, each bearing a single pair of legs, 

 and with long, many jointed antennee (Fig. 

 83). The mouth parts are adapted for bit- 

 ing. The opening of the poison gland is 

 on the first pair of legs, which are used 

 with the mouth parts. This order includes 

 the centipedes, as Litho'bius, common under 

 stones. The bite of, the true centipede 

 {Scolopen'dra) is fatal to insects and to 

 other small animals, their prey, and painful or even dangerous 

 to man. 



Fig. 83.— A centi- 

 pede. 



