Plate XL 



Fig. i. Piece of transverse section of a primary spine of Cidaris af finis. Obj. II. Oc. o. 



— 2. — - — - spines of Tromikosoma Koehleri\ a — b. sections of primary actinal 



spines, c. of an abactinal spine. Obj. II. Oc. I. 



— 3. Piece of transverse section of a primary spine of Porocidaris purpurata. Obj. II. Oc. I. 



— 4. — - - spines of Hygrosoma Petersii; a. section of a primary actinal 



spine, b. of an abactinal spine. Obj. II. Oc. I. 



— 5. Piece of transverse section of spines of Calveria kystrix; a. section of a primary actinal spine, 



b. of an abactinal spine. Obj. II. Oc. I. 



— 6. Transverse section of a primary spine of Hypsiechinus coronatus. Obj. II. Oc. III. 



— ■ 7. Piece of transverse section of spines of Phormosoma place7ita ; a. section of an abactinal spine, 

 b. of a primary actinal spine, lower part. Obj. II. Oc. I. 



— 8. Piece of transverse section of a primary spine of Arceosoma fenestration. Obj. II. Oc. I. 



— 9. — - - spines of Sperosoma Gritualdii; a. section of a primary actinal 



spine, b. of an abactinal spine. Obj. II. Oc. I. 



— 10. Transverse section of a primary actinal spine of Phormosoma placenta, outer part. The out- 



line indicates the circumference of the bag of skin. Obj. II. Oc. I. 



— 11. Spicule of a tube foot of Aroeosoma tesselatum. Obj. II. Oc. III. 



— 12. a. b. Spicules from the organs of Stewart of Stereocidaris ingolfiana. Obj. II. Oc. I. 



— 13. Spicules of a tube foot of Tromikosoma Koehleri. Obj. II. Oc. I. 



— 14. Piece of transverse section of a primary spine of Dorocidaris papillata, young specimen. 



Obj. II. Oc.o. 



— 15. Spicules of a tube foot of Arceosoma coriaceum; a. from [the outer, b. from the lower part 



Obj. II. Oc.HI. 



— 16. a — d. Spicules of the genital organs of Stereocidaris ingolfiana. Obj. II. Oc. I. 



— 17. Piece of a primary spine of a young Stereocidaris ingolfiana'. Obj. 00. Oc. o. 



— 18. Spicules of a tube foot, lower part, of Kamptosoma asterias (Ph. tentce*. Chall. St. 272). 



Obj. II. Oc. I. 



— 19. Spicules of a tube foot of Hapalosoma pellucidum. Obj. II. Oc. III. 



— 20. — — — - Asthenosoma varium. Obj. II. Oc. III. 



— 21. — - Porocidaris purpurata. Obj. II. Oc. I. 



— 22. - Cidaris affinis; a. from the outer, b — c. from the lower part. 



Obj. II. Oc. I. 



- 23. Piece of the intestine, with imbedded spicules, of Stereocidaris ingolfiana. Obj. II. Oc. I. 



— 24. — - transverse section of a primary spine of Dorocidaris (?) micans. Obj. II. Oc. I. 



— 25. Spicules of an abactinal tube foot of Phormosoma placenta. Obj. II. Oc. I. 



— 26. a — d. — of a tube foot of Dorocidaris papillata. Obj. II. Oc. III. 



— 27. - Hygrosoma Petersii. Obj. II. Oc. I. 



— 28. a— d. — - Stereocidaris ingolfiana. Obj. II. Oc. III. 



— 29. - Calveria hystrix. Obj. II. Oc. III. 



— 30. Piece of a primary spine with the crest of a young Stereocidaris ingolfiana. Obj. 00. Oc. o. 



— 31. - transverse section of a primary spine of Dorocidaris papillata, larger specimen. 



Obj. II. Oc.o. 



— 32. Piece of the crest of a primary spine of Stereocidaris ingolfiana. Obj. II. Oc. o. 



— 33. — - transverse section of a primary spine of Stereocidaris ingolfiana. Obj. II. Oc. I. 



