Plate XX. 



Fig. i. Tridentate pedicellaria of Echinus Alexandri. Obj. o. Oc. I. 



2. Spicules of Echinus Alexandri. Obj. V. Oc. I. 



3. Valve of a triphyllons pedicellaria of Strongylocentrotus drebachiensis. Obj. II. Oc. III. 



4. tridentate i.granulatus. Obj.o. Oc. I. 



5. ophicephalous Obj. II. Oc. III. 



6. tridentate Obj. o. Oc. I. 



7. triphyllous - Sterechinus Neumayeri. Obj. II. Oc. III. 



8. Spicules of Echinus elegans. Obj. V. Oc. I. 



9. Tridentate pedicellaria, small form, of Echinus elegans. Obj. II. Oc. o. 



10. Valve of a tridentate pedicellaria of Strongylocentrotus pulcherrimus. Obj. II. Oc. o. 



11. Tridentate pedicellaria of Sterechinus Neumayeri. Obj.o. Oc. I. 



12. Spicnles of Strongylocentrotus drebachiensis. Obj. V. Oc. I. 



13. Sphseridia of Obj. II. Oc. III. 



14. Valve of a globiferous pedicellaria of Strongylocentrotus purpuratiis, from the inside. Obj. II. Oc.o. 



15. Globiferous pedicellaria of Psammechimis variegatus. Obj. II. Oc. o. The skin full of spicules. 



16. Valve of a globiferous pedicellaria of Strongylocentrotus drebachiensis, from the inside. 



Obj. II. Oc. I. 



17. Spicules of Echinus affinis. Obj. V. Oc. I. 



18. Sphaeridia of Strongylocentrotus drebachiensis. Obj. II. Oc. III. 



19. Tridentate pedicellaria, large form, of Echinus elegans. Obj. o. Oc. o. 



- 20. Valve of a tridentate pedicellaria of Strongylocentrotus drebachiensis. Obj. o. Oc. I. 



- 21. triphyllous - Echinus affinis. Obj. II. Oc. III. 

 22. elegans. Obj. II. Oc. III. 



- 23. Stalk of a globiferous pedicellaria of Echinus elegans. Obj. II. Oc. I. 



24. Spine from the buccal plates of Echinus esculentus. Obj. o. Oc. o. 



25. Globiferous pedicellaria, the neck protruded, of Strongylocentrotus drebachiensis. The spicules 



are drawn only on the upper side of the head. Obj. o. Oc. I. 



- 26. Valve of a globifennis pedicellaria of Strongylocentrotus drebachiensis, from the side. Obj. II. Oc. I. 



- 27. ophicephalous large form, of Echinus Alexandri. Obj. II. Oc.o. 



- 28. - globiferous of Strongylocentrotus purpttrattts, from the side. Obj. II. Oc. o. 



- 29. Globiferous pedicellaria, the neck retracted, of Strongyloc. drebachiensis. Obj. o. Oc. III. 

 30. Spine of Echinus esculentus, the basal part. Obj. o. Oc. o. 



