58 VERMES. 



Order 2. Acanthocephata. Endoparasites without mouth or alimentary 

 canal. Possess a retractile hook-bearing proboscis. Sexes separate. A 

 single genus Echinorhynchus. E. gigas in the small intestine of the 

 pig ; the embryo is developed in the larva of the cockchafer. 



