Plate IV. 

 Synaptin^. 



Figures 1-7. Protarikyra duodactyla, sp. nov. 



Figure 1. Adult. X 3. 



2. Kadial and interradial pieces of calcareous ring. X 20. 



3. Anchor. X 156. 



4. Anchor-plate, as they most commonly appear. X 156. 



5. Fully developed anchor-plate. X 156. 



6. Early stage of development of anchor-plate. X 156. 



7. Supporting rods from tentacles. X 156. 



Figures 8—11. Protanl'yra ahymcola (Theel). 



Figure 8. Anclior. X 85. 



9. Anchor-plate. X 85. 



10. Tentacles. X 20. 



11. Supjjorting rods from tentacles. X 156. 



Figures 12-14. Prutanliyra hrychia (Vcrrill). 



Figure 12. ~A.nchor. X 55. 



13. Anclior-plate. X 55. 



14. Miliary granules. X 156. 



Figures 17-19 and 26. Si/napta maculata (Cham. & Eys.). 



Figure 15. Anchors. X !'5. 



16. Miliary granules. X 95. 



Figures 17-19 and 26. Synapla maculata Cham. & Eys. 



Figure 17. Anchor. X 65 (?). (From Theel, 1886a.) 



18. Miliary granules or rosettes. X 400 (?). (From Theel, 1886a.) 



19. Anchor-plate. X65(?). (From Theel, 1886a.) 



26. Ciliated fimnel from body-cavity. X 500. (From Semper, 1868.) 



Figures 20-22. Pohjpledana kefersteinii (Selenka). X 95. (From Semper, 1868.) 



Figure 20. Anchor-plate. 



21. Miliary granules. 



22. Anchor. 



Figures 23-25. Eiiapla lappa (Miiller). (From Theel, 1886a.) 



Figure 23. Miliary granules or rosettes. X 300 (?). 



24. Anchor-plate. X 225 (?). 



25. Anchor. X 225 (?). 



208 



