CONTENTS. 



PART I. 



SYSTEMATIC HBLMINTHOLOGY. 



CHAPTER I.— TURBELLABIA. 



ITature and extent of the subject — Leading terms employed — The Entozoa constitute a 

 peculiar /awwcs — Their distribution throughout time and s^Mce — Not yet found in a 

 fossil state — Classification of the Helminths — A new sub-class proposed — The Tur- 

 bellarians — Characters of the Planaridffi — G-enera — The Nemertidse, or ribbon 

 worms — -Their structure and habits— Genera— Concluding argument in favour of 

 associating the Turbellarians with the Helminths in the manner here proposed. 



P. 2—13 



CHAPTER II.— Teematoda. 



The Trematoda, or flukes — Aspect and habits — Distribution in mammals, birds, reptiles, 

 and fishes — Estimated number of species — Classification of the order — The family of 

 Monostomes — Their development and genera — The Distomes — Their anatomical 

 structure and development — Yan Beneden' s investigations respecting Distoina mili- 

 tare — Pagenstecher's researches — Genera ...... 14 — 32 



CHAPTER III.— Trematoda. 



Structure of particular Trematode types — Fasciola — G-asterostoma — Campula — Bilharzia 

 — ^Echinostoma — Family of the Tristomes — Then* development and Genera— The 

 Polystomes — Genera — The Gyrodactyles — "Wedl's researches respecting their orga- 

 nization — Development — Yon Siebold's and Yan Beneden's opinions contrasted. 



33—51 



