ON THE ANATOMY OF HISTIUOBDELLA HOMAIU. 



287 



On the Anatomy of Histriobdella Homari/ 



By 



Cresswell, Shearer, M.A., 



Trinity College, Cambridge. 



With Plates 17-20 and 5 Text-figures. 



Contents. 



1. Introduction, Material, and Methods 



2. Review of Literature and Remarks on Habits 



3. Description of the Nephridia . 



A. First Nephridium 



B. Second Nephridium 

 c. Third Nephridium 

 D. Fourth Nephridium 



4. Body-cavity and Nephridia 



5. Muscular System 



A. Longitudinal Muscles 



B. Special Muscles of the Generative Segment 

 c. Oblique Muscles 



6. Digestive System 



7. Nervous System . . 



8. Sense-Organs 



9. Reproductive System 



A. In the Male 



B. In the Female . . . 

 10. Conclusion and Summary 



PAGE 



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 346 



^ I have to thank the Director and members of the stafB of the Marine 

 Biological Association of Plymouth for their kind attention and interest 

 in my work while at Plymouth. 



