Plate VI. 



Fig. I. Stereocidaris iiigoljiana^ from above. '/i- 



— 2. — — - the side. '/j. 



— 3. Test of Stereocidaris mgolfiana. '/j. 



— 4. Apical area of — — ^/j. 



— 5. Ambulacral-processes of Stereocidaris ingoijiaua. ■/,. 



— 6. — - Dorocidaris papillata. '/i- 



— 7. Interainbulacral area - — — '/j. 



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



— 9- — " — - Cidaris affinis. -i/i- 



— 10. Interambulacral area of Cidaris affinis. ^j. 



— II. Piece of ambulacral area of Stereocidaris ingolfiana. -i/j. 



— 12. — - — - Porocidaris purpitrata. -»/i. 



