PLATE XVII. 



FIO. 



1, 2. MEMBRANIPORA CATENULARIA, p. 134. 



3, 4. MEMBRANIPORA MONOSTACHYS, p. 131 ; linear 

 form. See Plate XVIII. 



5., 6, 8. MEMBRANIPORA LACROIXII, p. 129; various states. 

 7. - , with marginal spines. 



