Plate XL 



Fig. i. Piece of transverse section of a primary spine of Cidaris affinis. 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 hystrix; 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 Phormo soma placenta; 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 fenestratum. Obj. II. Oc. I. 



9. - - spines of Sperosoma Grimaldii; 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. 



- ii. Spicule of a tube foot of Arceosoma 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. III. 



- 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. oo. Oc. o. 



18. Spicules of a tube foot, lower part, of Kamptosoma asterias (.Ph. tenue. 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 purprirata. 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. oo. 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. 



