TABLE OF CONTENTS 



Pages 



Introduction .-. 7 



Methods of Investigation 7 



Biology of the Bitter Root Valley 9 



Morphology of Trematodes Found 13 



Introduction 13 



Embryologj'^ 14 



Parthenitae (Sporocyst and Redia) 18 



Cercaria General 23 



Integument 27 



Parenchyma 29 



Musculature 30 



Armature 31 



Glands 32 



Excretory System 36 



Digestive System 43 



Genital System 44 



Nervous System 47 



Description of the Trematodes Infecting MoUusks of the Bitter Root Valley 57 



Introduction 57 



Monostomata 58 



Cercaria pellucida Faust 1917 58 



Cercaria konadensis Faust 1917 61 



Holostomata 62 



Cercaria flabelliformis Faust 1917 62 



Tetracotyle pipientis nov. spec 64 



Cercaria ptychocheilus Faust 1917 66 



Distomata 68 



Xiphidiocercariae 68 



Cercaria crenata Faust 1917 68 



Cercaria glandulosa Faust 1917 69 



Cercaria diaphana Faust 1917 71 



Cercaria dendritica Faust 1917 72 



Cercaria micropharynx Faust 1917 74 



Cercaria racemosa Faust 1917 75 



Echinostome Cercariae 76 



Cercaria trisolenata Faust 1917 76 



Cercaria biflexa Faust 1917 78 



Fvncocercariae 80 



Cercaria graciUima Faust 1917 80 



Cercaria tuberistoma Faust 1917 82 



Pathology 84 



Problems Presented 86 



Interrelation of Trematodes 86 



Relation of Trematodes to Other Groups 90 



Life Cycle of the Digenetic Trematodes 92 



Summary 94 



Species Described in this Paper 95 



Bibliography 96 



Explanation of Plates 102 



