PLATE XXXVII. 



1. Mellita testudinata. Club-shaped spines of the abactiiial svirface. 



2. Mellita testudinata. Sjiines of the actinal surface. 



3. Peronella decagonalis. .Spines of the actinal surface. 



4. Echinodiscus biforis. Club-shaped spine of the abactinal surface. 



5. Echinodiscus biforis. Transverse section of same. 



6. Echinodiscus biforis. Transverse section of smaller spine. 



7. Echinarachnius mirabilis. Spine of abactinal surfoce. 



8. Echinarachnius mirabilis. Transverse section of same. 



9. Echinanthus rosaceus. Longitudinal section of spine. 



10. Echinanthus rosaceus. Transverse section of same. 



11. Echinanthus rosaceus. Magnified base of spine. 



12. Rhynchopygus pacificus. Transverse section of spine near ambitus. 



13. Maretia planulata. Transver.se section of long spine from abactinal surface. 



14. Marieta planvilata. Spines of abactinal interambulacral surface. 



15. Echinocardium australe. Transverse section of abactinal interambulacral spine. 



16. Spatangus purpureus. Longitudinal section of abactinal interambu^lacral spine. 



17. Lovenia elongata. Tip of one of the serratetl spines of the abactinal surface. 



18. Lovenia elongata. Small, curved, and spathiform spine of actinal surface. 



19. Brissus unicolor. Interambulacral spine from the abactinal surface. 



20. Metalia sternalis. Interambulacral spines from the abactinal surface. 



