PLATE VII. 



Echinus gracilis, / 1-6". 



1. Abactinal system of specimen, measuring 10.5°"- in diam., magnified. 



2. Part of test of same specimen magnified, showing arrangement of pores, and formation 



of secondary and miliary tubercles. 



3. Abactinal system of specimen, measuring 43""- in diam., magnified. 



4. Part of test of same, magnified. 



5. Abactinal system of specimen measuring r2.7°'°'- in diam., magnified. 



6. Abactinal system of specimen somewhat larger {'^'). 

 6». Abactinal system of large specimen \. 



Toxopneustes variegatus, /. 7-22. 



7. Specimen measuring 4.74"°- in diam. from actinal pole, magnified. 



8. Magnified part of test of same specimen as fig. 7. 



9. Same (fig. 7) seen from abactinal side. 



10. Specimen measuring 6.2""- in diam. from abactinal pole, magnified. 



11. Magnified part of test of same (fig. 10). 



12. Spine of same, magnified. 



13. Actinal side of same, magnified. 



14. Specimen measuring 10.9"°- from actinal pole, magnified. 



15. Magnified part of test of same (fig. 14). 



16. Same specimen (fig. 14) from abactinal side. 



17. Abactinal system of specimen, from Florida (3^5). 



18. Abactinal system of specimen somewhat older (J). 



19. Abactinal system of larger specimen (|). 



20. Buccal membrane of same (^). 



21. Portion of test of specimen, measuring SB""' in diam. 



22. Portion of test of specimen, measuring 57""' in diam. 



