PLATE XXIV. 



Dorocidaris papillata, f. 1 - 8. 



1, 2, 3, 4. Different stages of the long-stemmed, slender ambulacrul pedicellarite. 

 3". Internal viaw of Fig. 3, the front prong removed. 



5. One of the short-stemmed, stout jiedicellariw of the abactinal system. 



6. Internal view of one of the prongs of Fig. 5. 



7. One of the short, long-stemmed ambulacral pedicellarise. 



8. Side view of one of the prongs of Fig. 7. 



FhyUacanthus baculosa, /. 9. 



9. Interior view of one of the forks of a short, long-stemmed ambulacral pedicellma. 



Fhyllacanthns dubia,/. 10. 



10. Interior view of one of the forks of a short, long-stemmed ambulacral pedicellaria. 



Porocidaris purpurata, /. 11. 



11. Head of one of the short, long-stemmed ambulacral pedicellariae. 



Goniocidaris geranioides, /. 12, 13. 



12. Internal view of one of the short-stemmed interambulacral pedicellariae. 



13. Outside view of same. 



Astbenosoma varium, /. 14- 



14. Terminal portion of one of the forks of a long-stemmed interambulacral pedicellaria. 



Strongylocentrotus Drobachiensis, /. 15 -2^. 



15. Side view of prong from one of the large-headed, long-stemmed pedicellariaj. 



16. Interior view of same. 



17. Interior of a prong of younger pedicellaria. 



18. Profile of one of prongs of Fig. 24. 



19. Interior of prong of a stout-headed actinal pedicellaria. 



20. Limestone rod of stem of large-headed pedicellaria. 



21. Interior of prong of young actinal pedicellaria. 



22, 23. Interior of prong of two stages of large-headed pedicellariae. 



24. Tridactyle, long-stemmed interambulacral pedicellaria. 



Strongylocentrotus Uvidus, /. 25. 



25. Profile of large-headed, long-stemmed interambulacral pedicellaria. 



Strongylocentrotus nudus, /. 2G - 30. 



26. Interior of prong of long-stemmed, large-headed interambulacral pedicellaria. 



27. One of the stout-headed, short-stemmed actinal pedicellarise. 



28, 29. Interior and profile of prong of a large-headed, long-stemmed pedicellaria somewhat 

 younger than Fig. 26. 

 30. Interior of a prong of a still younger pedicellaria. 



