382 THE AMERICAN MONTHLY [Dec, 



3. CARPOSPH^RA. 



Pores hexagonal, 5-6 on the quadrant infundibulum. 



Pores circular, 6-8 on the quadrant entactinia. 



Pores circular, 8-12 on the quadrant modesta. 



Pores irregular, roundish, 2-4 times as broad as the bars nohilis. 



4. THECOSPH^RA. 



Pores circular, hexagonally framed ; shells connected by 12 radial beams 



favosa. 



Pores circular ; shells connected by 4 radial beams medusa. 



5. RHODOSPmERA. 



Pores irregular, roundish ; diameter of shell 0.4 palliata. 



6. CROMYOyPH.ERA. 



Pores circular ; surface thorny cepa. 



Pores irregular, roundish : surface smooth sccrrodonium. 



7. CARYOSPH.ERA. 



Pores circular ; six concentric spheres hexalepas. 



8. XIPHOSPH.ERA. 



Pores circular, 15-20 on the half equator : bristle like spines juno. 



Pores circular, 28-32 on the half equator ; conical thorns gigantea. 



9. XIPHOSTYLUS. 



Pores circular, 8-10 on the half equator anhinga. 



10. SATURNALIS. 



Pores circular, 8-10 on the half equator ; ring without spines or thorns, cyclns. 

 Pores circular, 12-16 on the half equator ; ring with spines or thorns, .troch- 

 oides. 



11. STYLOSPH^RA. 



Pores circular, 10-15 on the half equator ; polar spines prismatic hispida. 



Pores circular, 8-10 on the half equator ; polar spines conical liostylus. 



12. SPH.EROSTYLUS. 



Pores circular, 10-12 on the half-equator liostylus. 



Pores circular, 8-10 on the half-equator ; polar spines S like liexuosus. 



13. STAUROSPH-ERA. 



Pores circular, 20-22 on the quadrant ; surface smooth petri. 



Pores circular, 8-10 on the quadrant ; surlace smooch simonis. 



Pores irregular, roundish, 4-6 on the quadrant; surface smooth, apostolorum. 



Pores irregular, roundish, polyonally framed, 5-7 on the quadrant ; surface 



spiny thaddaei. 



