Plate VI. 



Fig. I. Stereocidaris ingoljiana^ from above. Vi- 



— 2. — — - the side, '/i- 



— 3. Test of Stereocidaris ingolfiana. Vi- 



— 4. Apical area of — — ^/i. 



— 5. Ambulacral-processes of Stereocidaris ingolfiana. '/i- 



— 6. — - Dorocidaris papillata. Vi- 



— 7. Interainbulacral area - — — Vi- 



— 8. Piece of ambulacral area of Dorocidaris papillata. ^ji. 



— g. — - — - Cidaris af finis, ^/i. 



— 10. Interainbulacral area of Cidaris af finis, ^ji. 



— II. Piece of ambulacral area of Stereocidaris ingolfiana. 4/,. 

 12. — - — - Porocidaris purpitrata. ^/j. 



