62 Trans. Acad. Sci. of St. Louis. 



Taking into account the interrelations of the parasites 

 and organisms affected. 



Depending upon the position of the parasites in relation to thetr 

 hosts. 



Endoparasites. 



Sarcoptldae (In part). 

 Cytolelchidae (?). 

 Demodecidae (?). 

 Ectoparasites. 

 Cutlcolata. 



Harpyrhynchus, Psorergates. 



Gekohia. 



Larvae of Rhyncholophldae, Trombidildae, Hydra- 



chnldae, Halacarldae. 

 Ixodldae, 



Parasitic Tarsonemidae. 

 Sarcoptldae (mostly). 

 Cytolelchidae (?). 

 Demodecidae. 

 Vllllcolata. 

 Myobia. 

 LIstrophorldae. 

 Plumlcolata. 



Picobia, Syrlngophilus. 

 Analgesidae. 

 Depending upon the duration or time of parasitism. 

 Erratic parasites. 



Semlparasitlc Tetranychldae. 

 Atax (?). 



Some of the Gamasidae and some of the Uropodidae. 

 Some of the Tarsonemidae. 

 Hemisarcoptes. 

 Periodical parasites. 

 Nocturnal. 



Argasidae. 



Dermanyssldae (In part). 

 Diurnal. 



(Data upon habits In this regard wanting.) 



During a definite stage or stages in the life cycle 

 of the species attacked. 

 During the egg stage. 

 Histiostoma berghl. 

 Hemisar copies. 

 During the fetal stage. 

 During the immature stage. 

 Pediculoides ventricosua. 

 During adult stage. 



