CONTENTS. 



Page. 



Summary 7 



Introduction 8 



Family Filariidse 9 



Subfamily Arduenninac 9 



Genus Arduenna 9 



Arduenna slrongylina 10 



Arduenna dentata 20 



Genua Physocephalus 21 



Physocephalus sexalatus 21 



Comparison of Physocephalus sexalatus and Arduenna strongylina 31 



Other species referred to Physocephalus sexalatus 31 



Distribution of Arduenna strongylina and Physocephalus sexalatus in the United 



States , 32 



Relative frequency of the two species 34 



Lesions associated with Arduenna strongylina, Arduenna dentata, and Physo- 

 cephalus sexalatus 34 



Life history 3g 



Preventive measures .' 37 



Medicinal treatment 37 



Key to the round worms parasitic in domestic swine 38 



Classified list of the roundworms parasitic in domestic swine 41 



Bibliography 45 



5 



