ARACHNIDA 



541 



The legs resemble the appendages of Peripatus and each is termin- 

 ated by two forked claws. The last pair are terminal and the anus opens 

 between them. The nervous system consists of suprapharyngeal, sub- 

 pharyngeal and four pairs of trunk ganglia, the latter corresponding 

 to the appendages. 



Physiologically the Pantopoda are interesting in their capacity for 

 resisting desiccation. Like the rotifers and nematodes with which 

 they are associated in habitat they shrivel up with loss of water, 

 absorbing it again and returning to life at the next rain. 



Class PENTASTOMIDA 



Elongated vermiform parasites with a secondary annulation and two 

 pairs of claws at the sides of the mouth; without respiratory or 

 circulatory systems. 



an. ->: 



Fig. 371. A, Demodex folliculorum, ventral view. After Blanchard. A mite 

 living in the hair follicles of man and domestic animals. B, Linguatula 

 taenioides. After Leuckart. Ventral view, at the stage when it is eaten by 

 the second host. al.c. alimentary canal; an. anus; cl. claws; M. mouth. 



The commonest example, Linguatula taenioides, lives in the nasal 

 passages of carnivorous mammals; the larvae, in which the claws of 



