Plate 46. 



1-4. Fodophora pedifera Agass. 



1. The odd anterior ambulacrum of a denuded specimen 55 mm. in diameter. 



2. Pore near the actinal system, from the same specimen. 



3. Pore at the ambitus. 



4. One of the pores of the ninth plate from the actinal system. 



5-8. Fodophora atrata Agass. 



5. The odd anterior ambulacrum of a denuded specimen 46 ram. in diameter. 



6. Pore near the actinal system, corresponding to the pore of fig. 5. 



7. Pore at the ambitus. 



8. One of tlie pores of the eighth plate from the actinal system. 



9-12. Colobocentrotus Stimpsoni A. Ag. 



9. The odd anterior ambulacrum, of a denuded specimen 65 mm. in diameter. 



10. Pore near the actinal system corresponding to the pore of fig. 5. 



11. Pore at the ambitus. 



12. One of the pores of the eleventh plate from the actinal system. 



