SPONGES 



llyalonema p. 

 from Japan, with 

 symbiotic polyp* 

 (Palythoa) growing 

 on the upper por- 

 tion of the root- 

 tuft. (After Agas- 

 siz.) J. 



FiO. 18. 

 RtgadrtVa phoenix, O.S. (After Agassiz.) J. 



