AKTHROPODA 



189 



Arthropoda. They arc little, wormlike animals, commonly from 

 five to six centimeters long, terrestrial, living in clamp places 

 under decaying wood or beneath stones, and are nocturnal in 

 their habits. The body is not 

 segmented, but the surface is 

 transversely wrinkled, and 

 there are many pairs of short, 

 stumpy legs, externally ringed 

 but not jointed, and each 

 terminating in a pair of chiti- 

 nous claws. The head bears 

 a pair of antennae, a pair of 

 eyes, two jaws, and two 

 papillae, one on each side of 

 the mouth. The anus is at 

 the posterior end of the body. 

 The respiration is by means 

 of tracheae, which open on the 

 surface of the body by stig- 

 mata, which are very variously 

 arranged in the different 

 species. Thus by reason of 

 their respiratory organs these 

 animals are undoubted Tra- 

 cheata. The excretory organs, 

 on the other hand, are typical 

 nephridia, such as occur in 

 the Annelida, and thus demon- 

 strate a relationship to these 

 worms (Fig. 186). Peripatus 

 is widely distributed and has 

 been found in Africa, South 

 America, the West Indies, 

 New Zealand, and Australia. 



OCX glrf 



Fie. 186. Peripatus. Dorsal view of internal 

 organs dissected, an, anus; ant, antenna-, 

 brn, brain ; cox.gld, coxal gland ot the seven 

 teenth leg; $ gen, male genital aperture; 

 tie. Co, nerve cord ; neph, nephridia ; phar, 

 pharynx , sal.gld, salivary gland ; sl.gld, slime 

 gland; stow, stomach. (From Parker and 

 Haswell's Manual.) 



CLASS II. MYRIAPODA 



The Myriapoda (Gr. /xvpios, countless, and irovs, foot) are 

 Tracheata possessing an elongated body, sometimes flattened 



