CONTEMPORAEIES AND SUCCESSORS OF EOZOON. 153 



\. 39. ArchcBOcyathus 'profundus — showing the base of attach- 

 ment and radiating chambers. {After Billings.) 



Fig. 40. Archaocyathus Atlanticus — showing outer surface and 

 longitudinal and transverse sections. {After Billings.) 



