PLATE IV. 



FIG. 22. Teti-fibothrhiK wrigJiti, Leiper and Atkinson ; ex Pygoscelis addiae. Complete but immature 

 strobila, showing characteristic suckers, and the arrangement of the testes in the segments. 



FIG. 23. Anomotaenia zederi, ex Aptenodytes forsteri. Immature form from cyst. 



F IG . 24. A. zederi. Cyst dissected out from intestinal wall and showing long neck and opening into 

 lumen of the gut of the host. 



FIG. 25. Tetrabothrius nelson!, Leiper and Atkinson ; ex Phoebetriu pfilpcbrata. Segment, showing a, 

 genital atrium ; b, vas deferens ; c, cirrus ; t, testes ; v, vagina ; vs, vesicula seminalis. 



FIG. 26. Tetrabothrius creani, Leiper and Atkinson : ex (Estrelata trinifatis ; head, showing suckers. 

 FIG. 27. T. i-n-nni. Segments. 



FIG. 28. Tetrabothrius priestlei/i, Leiper and Atkinson ; ex Frigate Bird (Fregata aquila or F. arid). 

 Immature segments ; c, cloaca ; xp, cirrus ; /, testes. 



FIG. 29. Tetrabothrius catherinae, Leiper and Atkinson ; ex (Estrelata trinitatis ; scolex. 

 FIG. 30. T. catherinae. Segments ; c, cloaca ; sp, cirrus ; t, testes. 



FIG. 31. Tetrabothrius cylindraceus, ex Megalestris maccormicM. Segments, showing horse-shoe arrange- 

 ment of testes ; c, cloaca ; sp, cirrus ; /, testes ; yg, yolk-gland. 



