Platk 12". 



1-3. Doroeidaris aifinis A. Ag. 



All the figures are from a single individual. x 70. 



1. Tip of valve of a large podicellaria of e.\ac;tly the same appearance as the small 



pedicellaria of the same individual. 



2. Tip of valve of an ordinary large globiferous pedicellaria, but the opening is not quite 



terminal. 



3. Tip of valve of a somewhat larger pedicellaria with the opening distinctly terminal. 



4-6. Doroeidaris Blakei A. Ag. 

 All the figures are from a single individual, to show the diversity in the form 



of the opening, x 70. 



7-9. Centroeidaris Doederleini A. Ag. 



7. Valve of an ordinary large globiferous pedicellaria ; side view, x 70. 



8. Valve of jieculiar large globiferous pedicellaria; inner view, x 70. 



9. Valve of tridentate pedicellaria : side view. < 70. 



10-19. Aetinal Primary Spines. x 5. 

 The even numbers show the abactiual side ; the odd numbers, the aetinal side. 



10. 11. Stephanocidaris bispinosa A. Ag. 



12, 13. Stephanocidaris hawaiiensis A. Ag. and Clark. 



14, 15. Phyllacanthus annulifera A. Ag. 



1(). 17. Phyllacanthus baculosa A. Ag. 



18, 19. Acanthocidaris hastigera A. Ag. and Clark. 



