32 



Plate I 



Unless otherwise stated, figures are magnified thirty diameters. 



Page 



Fig. 1. Amplexopora solitaria. Tangential section 17 



Fig. 2. Atactoporella densa. Tangential section, X 60 18 



Fig. 3. Amplexopora solitaria. Vertical section 17 



Fig. 4. Atactoporella densa. Vertical section 18 



Fig. 5. Calloporella vacua. Tangential section 19 



Fig. 6. Calloporella vacua. Vertical section 19 



Fig. 7. Hallopora aequalis. Deep tangential section 19 



Fig. 8. Hallopora onealli creditensis. Tangential section 20 



