Plate II. 



Fig. 1. Apical area of Plenrcchinus Döderlcini Zeiss, a*. Oc. 2. 



— 2. Part of ambulacral area of Pleurcchiniis siamensis (Torres Strait). Zeiss, a*. Oc. 3. 



— 3. — - — — - Slfjihanocidaris bispinosa. Zeiss, a'. Oc. 1. 



— 4. — - — — - Pleurechiniis scillœ. Zeiss. , a'. Oc. 2. 



— 5. Apical area of Pleurechinus maculaliis. Zeiss, a*. Oc. 2. 



— Ü. — — - — variegatus. Zeiss. - — 



— 7. Part of interambulacral area of Pleurechinus Döderlcini. Zeiss, a'. Oc. 3. 



— 8. — - ambulacral — - — — Zeiss. - — 



— 9. — - interambulacral — - — siamensis (Torres Strait). Zeiss, a'. Oc. 3. 



— 10. Apical area of Pleiirccliiims scillw. Zeiss, a*. Oc. 2. 



— 11. — — - Gymncchiiius pnlchellus. Zeiss, a'. Oc. 1. 



— 12. — — - Pleurechinus scillœ (Muscat). Zeiss, a'. Oc. 2. 



— 13. Part of interambulacral area of Pleurechinus scillœ. Zeiss, a'. Oc. 2. 



— 14. Apical area of Pleurechinus siamensis (Torres Strait). Zeiss, a*. Oc. 3. 



— 15. — — - - — (Gulf of Siam\. Scib. Obj. Oil. Oc. 00. 



— 16. Chælodiadema japonicum. abactinal side (from a photograph). 



— 17. Interambulacral area of .Slephiinocidaris bispinosa. '/i. 



— 18. Apical area of StepluuKjcidaris bispinosa. '/i. 



— ID. Chælodiadema japonicum. actinal side (from a photograi)h). 



— 20. Secondary spine of Microcijphus ziyzag. Seib. Obj. 0. Oc. I. 



— 21. The point of a primary spine of Amhlgpneustes pallidas. Seib. Obj. 11. Oc. I. 



— 22. — — — — - Pleurechinus siamensis. Seib. Obj. 11. Oc. 111. 



— 23. — — — — - Mierocyphus niaculatus. — — 



— 24. — — — — - Holopneiisles purpurascens. Obj. AA. Oc. 3. 



— 25. — — ■ — — - Microcyiihus zigzag. Seib. Obj. II. Oc. 1. 



— 26. — — secondary — - — — — — — III. 



— 27. — — primary — - Amblypneusles formosus. Seib. Obj. 0. Oc. III. 



— 28. Primary spine ot Mierocyphus maculatus. Seib. Obj. 0. Oc. 0. 



