PLATE IX a . 

 Aspidodiadema Jacobyi A. Ag. 



Specimen covered with spines seen from the abactinal pole, natural size. 



Denuded specimen, 23 mm. in diameter, seen from the abactinal side. 



The same as Fig. 2, seen from the actinal side. 



Abactinal system of same, somewhat more magnified. 



Actinal system of same. 



Magnified portion of test of same, seen facing one of the interambulacral areas. 



Same as Fig. 6, seen facing one of the ambulacra! areas. 



Portion of test, seen facing one of the ambulacral areas, showing the suckers and the sheathed 

 pedicellari;e. 



One of the sheathed pedicellarise, greatly magnified. 



The same, seen in profile. 



Aspidodiadema denuded, seen in profile, 12 mm. in diameter. 

 Fig. 11. The same as Fig. 10, seen from the abactinal pole. 

 Fig. 12. The same as Fig. 10, seen from the actinal side. 

 Fig. 13. Genital ring of same, somewhat more magnified. 

 Fig. 14. Actinostome of same. 

 Fig. 15. Portion of test of same, seen in profile, somewhat more magnified than in Fig. 10, seen facing 



one of the ambulacral areas. 

 Fig. 16. The same as Fig. 15, seen facing one of the interambulacral areas. 

 F'ig. 17. Young specimen fi mm. in diameter, seen from the abactinal side. 

 Fig. IS. The same as Fig. 17, seen in profile. 

 Ii ,19. The ame, seen from the actinal side. 



[Jig. 20. Genital ring of a young specimen 3 mm. in diameter, before the formation of the genital or 

 oi 1 1 lir pores, showing the anal proboscis. 



