Plate XXI. 



Fig. i. Valve of a tridentate pedicellaria of Pseudoboletia maculata. Obj. o. Oc. I. 



2. - Psammechinus -uerntculatus. Obj. II. Oc. I. 



3. - Tripneustes esculentus. Obj. II. Oc. o. 



4. - Gymnechinus Robillardi, from the side. Obj. II. Oc. I. 

 5. ophicephalous - - Pseudoboletia maculata. Obj. II. Oc. I. 



6. tridentate - Anthocidaris homalostoma. Obj. II. Oc. o. 



7. - Gymnechinus darnleyensis. Obj II. Oc. I. 



8. - Pseudocentrottis depressus. Obj. o. Oc. o. 

 _ 9. Obj. II. Oc. o. 



10. - Psammechinus variegatus. Obj. II. Oc. o. 



ii. - Gymnechinus Robillardi, from the inside. Obj. II. Oc. I. 



12. Spicnles of Sphcerechinus granularis. Obj. V. Oc. III. 



13. Valve of a globiferous pedicellaria of Toxopneustes pileohis. Obj. II. Oc. o. 



14. Spicules of Pseudocentrotiis depressus; a. from the tube feet, b. from the pedicellarise. 



Obj. V. Oc. o. 



15. Valve of a tridentate pedicellaria of Pseudocentrotus depressus. Obj. II. Oc. o. 



16. - Tripneustes esculentus. Obj. II. Oc. o. 



17. - Pseudoboletia maculata, small form. Obj. o. Oc. I. 



18. Plates from the bnccal membrane and the gills of Echinus Alexandria a. from the buccal 



membrane inside of the bnccal plates, b. c. from the gills. Obj. II. Oc. I. 



19. Piece of the stalk of a pedicellaria of Echinus Alexandri. Obj. V. Oc. I. 



20. edge of a tridentate pedicellaria of Ech. Alexandri. Obj. V. Oc. III. 



21. Spicules of Toxopneustes pileolus ; a. from globiferons pedicellariae, b. from tube feet, c. from 



the buccal membrane. Obj. V. Oc. I. 



22. Valve of an ophicephalous pedicellaria of Tripneustes esculentus. Obj. II. Oc. I. 



23. Spicules from pedicellariae of Gymnechinus darnleyensis. Obj. V. Oc. III. 



- 24. - Gymnechinus Robillardi; a. from pedicellarise, Obj. V. Oc. I, b. from the buccal 



membrane. Obj. II. Oc. I. 



25. Piece of the edge of a tridentate pedicellaria of Echinus acutus, var. Flemingii. Obj. V. Oc. III. 



26. stalk of a pedicellaria of Echinus acutus, var. Flemingii. Obj. V. Oc. I. 



27. Plate from the buccal membrane, outside of the buccal plates, of Echinus Alexandri. Obj. II. Oc. I. 



28. Spicules from pedicellarise of Psammechinus verruculatus. Obj. V. Oc. III. 

 . 29. - Pseudoboletia maculata. Obj. V. Oc. I. 



30. - tube feet of Anthocidaris homalostoma. Obj. V. Oc. o. 



31. - globiferous pedicellaria of Psammechinus variegatus', a developmental series. 



Obj.V. Oc. III. 



32. - tube feet of Parasalenia gratiosa. Obj. V. Oc. I. 



23- of 7"ripneustes esculentus; a. from globiferous pedicellarise, b. from tube feet, c. d. from 



the buccal membrane. Obj. V. Oc. I. 



34. Valve of a tridentate pedicellaria of Sph&rechinus granularis. Obj. o. Oc. I. 



_ 35. globiferous from the side. Obj. II. Oc. o. 



36. - Gymnechinus darnleyensis. Obj. II. Oc. III. 



37. - Sphcerechinus granularis, from the inside. Obj. II. Oc. o. 



38. - Psammechinus variegatus, - Obj. II. Oc. I. 

 ^9. - Tripneustes esculentus. Obj. II. Oc. I. 



40. - Psammechinus variegatus, from the side. Obj. II. Oc. I. 



41, tridentate - Toxopneustes pileolus. Obj o. Oc. o. 



