Plate 44. 



1-12. Colobocentrotus Stimpsonl A. Ag. 



1. Lantern seen from above. 



2. The same as 1, seen in profile. 



3. One of the pyramids, seen from the exterior. 



4. The same as 3, seen from the interior. 



5. The same, seen in profile. 



6. The same, seen from above. 



7. a. Epiphysis of pyramid, from the interior, b. pyramid, in profile, from the interior. 



8. a. Epiphysis of pyramid, from the exterior, b. pyramid, in profile, from the exterior. 



9. Edge of the corrugated surface of pyramid somewhat more enlarged. 



10. a. Groove of tooth, b. tooth seen in profile. 



11. a. The brace, seen from above, b. seen in profile, c. from below, d. endwise. 



12. a. Compass seen in profile, b. seen from above. 



All the figures from a denuded specimen 65 mm. in diameter. 



Bonin Ids., Captains Ringgold and Rodgers, N. P. Ex. Ex., Dr. Wra. Stimpson Coll. 



