66 * PROCEEDINGS OF THE NATIONAL MUSEUM vol.70 



Plate 1 

 Ligula intestinalis (Linnaeus) from PodUytnhus podiceps 



Fig. 1. Anterior end of strobile, sharp-pointed type ; breadth at x-x 0.4 mm. 



2. Anterior end of strobile, bluntly rounded type ; breadth at x-x 1 mm. 



3. Transverse section, about 0.1 mm, from anterior end ; longest diameter 



of .section 1.36 mm. 



4. Transverse section showing genitalia ; camera lucida drawing, details 



added from adjoining sections ; dorso-ventral diameter 0.7 mm. 



ScJiistocephalus soUdus (C. F. Miiller), from Podilinnhus podiceps 

 5. Anterior end of strobile ; breadth at base of first segment 1 mm. 

 Tetrabothrius cylindraceus (Rudolphi) 



6. Scolex ; maximum breadth 0.35 mm., from Larus argentatus. 



7. Adult proglottis, ventral view ; breadth 0.93 mm. ; from Sterna hirundo. 



8. Dorsal view of same. 



9. Frontal section of adult proglottis ; breadth 0.98 mm. 



10. Transverse section in vicinity of genital pore ; diameter of cirrus-pouch 

 0.04 mm. 



Plate 2 



Tetrabothrius cylindraceus (continued). 



Fig. 11. Diagram of female genitalia. 



12. Maturing proglottides; breadth 1.56 mm. 



13. Mature proglottis ; breadth 1.82 mm. 



Tetrabothrius heteroclitus (Diesing). 



14. Scolex ; breadth 0.45 mm., from Pufflnus borealis. 



15. Transverse section of scolex ; greater diameter 0.46 mm. 



16. Transverse section of proglottis ; longer diameter 0.44 mm. 



17. Details of body wall of same ; camera lucida drawing, Zeiss 2/D. 



18. Transver.se section of genital cloaca ; diameter of cirrus-pouch 0.041 



mm. ; from Nycticorax nycticorax naevius. 



19. Ripe proglottides, posterior to proglottis shown in fiigure 20; breadth 



0.34 mm. ; from Pufflnus griseus. 



20. Adult proglottis ; maximum breadth 0.27 mm. 



Plate 3 

 Tetrabothrius heteroclitus (continued) 



Fig. 21. Frontal section of ripe proglottides ; breadth 1.33 mm. 



22. Genital cloaca and cirrus-pouch from frontal section of adult proglottis; 



diameter of cirrus-pouch 0.045 mm. 



Tetrabothrius ma^rocephalus (Rudolphi) 



23. Scolex ; greatest breadth 0.73 mm., from Colymbus auritus. 



24. Transverse section of scolex; longer diameter 0.81 mm. 



25. Transverse section of immature proglottis ; longer diameter 0.98 mm. 



26. Transverse section of adult proglottis ; longer diameter 0.79 mm. 



(Pencil sketch of this figure misinterpreted; lateral diameter of 

 vitelline gland too great.) 



