Plate XXI. 



Fio-. I. Valve of a tridentate pedicellaria of Pseudoboletia iiiacnlata. Obj. o. Oc. I. 



2. — — — — - Psammechinus verriccttlatiis. Obj. II. Oc. I. 



-!. — — — - Tn'pneustes esculentus. Obj. II. Oc. o. 



A , — — — - Gymuechitius Robillardi^ from the side. Obj. II. Oc. I. 



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



_ 6. — — tridentate — - Anthoczdaris hotnalostoma. Obj. II. Oc. o. 



/• 



— — — - Gymnechinns darnieyensis. Obj II. Oc. I. 



8. — — — - Pseiidocentrotiis depressns. Obj. o. Oc. o. 



g. _ _ _ _ - - — Obj. II. Oc.o. 



10. — — — — - Psainmechiims vayiegatus. Obj. II. Oc.o. 



11. — — — - Gyimieclu'iiHs Robtllardi, from the inside. Obj. II. Oc. I. 



12. Sisicules of Sphærechinits granularis. Obj. V. Oc. III. 



13. Valve of a globiferous pedicellaria of Toxopneiistes pileolns. Obj. II. Oc. o. 



14. Spicules of Pseitdncentrotus depressns; ■&. from the tnbe feet, b. from the pedicellariæ. 



Obj. V. Oc.o. 



15. Valve of a tridentate pedicellaria of Pseudocentrotiis depressns. Obj. II. Oc.o. 



16. — — — - Tripneiistes esculentus. Obj. II. Oc. o. 



1-7 ^ — - Pseudoboletia maculata, small form. Obj. o. Oc. I. 



18. Piates from the buccal menibrane and the gills of Echinus Alexandri; a. from the buccal 



membrane inside of the bnccal piates, 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 globiferous pedicellariæ, b. from tube feet, c. from 



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



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



23. Spicules from pedicellariæ of Gynuiccliinus darnieyensis. Obj. V. Oc. III. 



24. — - Gymnechinus Robillardi; a. from pedicellariæ, 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 bnccal nrembrane, outside of the buccal piates, of Echinus Alexandri. Obj. II. Oc. I. 

 2S. Spicules from pedicellariæ of Psammechinus verruculatus. Obj. V. Oc. III. 



2Q. — - — - 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. 



33. _ of Tnpneustes esculentus] a. from globiferous pedicellariæ, b. from tube feet, c. d. from 



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



34. Valve of a tridentate pedicellaria of Sphærechinus granularis. Obj. o. Oc. I. 

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



o^ 



16. — — — - Gymnechijius darnieyensis. Obj. II. Oc. III. 



-3 j. _ — - Sphærechinus granularis, from the inside. Obj. II. Oc. o. 



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



— 39- 



TripJieustes esculentus. Obj. II. Oc. I. 



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



- 41- 



— tridentate — - Toxopneustes pileolus. Obj o. (^c. o. 



