ARACHNIDA 469 



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. 



The commonest example, Linguatula taenioides, lives in the nasal 

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



ale. 



an.--- 



Fig. 347. A, Demodex folliculoru?n, ventral view. After Blanchard. Amite 

 living in the hair follicles of man and domestic animals. B, Li7iguatiila 

 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 adult are borne on prominences which may be called limbs, live 

 in other mammals, chiefly herbivorous. The eggs are passed out of 

 the host, the larvae climb on to plants and are eaten by hares or 

 rabbits; they traverse the wall of the gut and encyst in other tissues, 

 often the liver. After a period of growth they wander once more 

 through the body ; they may at this stage be eaten by the second host 

 and after wandering through the body reach the nasal passages. The 

 larvae do resemble certain parasitic mites (Fig. 347 A) and it is for 

 this reason this group has been classed with the arachnids. 



