Plate VI. 



Fig. I. Echinosigra (Pourtalesia) phialc, abactinal side. 7/,. (For the apical system and adjoining 



plates, comp. PI. VII. Fig. 7.) 



— 2. — — — side view. 7/1. 



— 3. — — paradoxa, actinal side. '-^/i. 



— 4. — — — side view, '-^i- 



— 5. — — ■ — abactinal side. '-^i. 



— 6. — — — side view, ^'^i- 



— 7. — — pliiale, actinal side. 7/j. 



— 8. Plexechinus hirsutus, end view. ^/i. 



— 9. — — actinal side. ^/i. 



— 10. Urechinus naresianus, actinal side. '•s/j. 



— II. — — _ _ 1-5/,. 



— 12. Plexechinus hirsutus, abactinal side. Yi. 



— 13. - - - - Vi- 



— 14- — — side view. ^j. 



— 15. - _ _ _ 2/^. 



— 16. — — actinal side. '-s/,. (Not the same specimen as Figs. 12 and 15). 



— 17. Echinosigra (Pourtalesia) paradoxa, abactinal side. 7i- (For the apical system and adjoining 



plates, comp. Text-fig. 14, p. 75.) 



— 18. — — — abactinal side. '-^i. 



— 19- — — — side view. ^j. 



— 20. — — — actinal side. ■•'^/i. 



— 21. - - - _ _ 6/^. 



