PLATE IV. 



Fig. 



1. Dimorphoseris ooKUca, Duncan. (Inferior Oolite.) (Page 22.) 



2. Calicular surface. 



3. A calice, magnified. 



4. Synopticula?, magnified. 



6.1 



7 I 



}>Corallum and details of Thamnastrcea Walcotti, Duncan. (Inferior Oolite.) (P. 19.) 



o. 



9. 



10. 

 11. 



12 



\ Thamnastrcea Manseli, Duncan. (Inferior Oolite.) (Page 20.) 

 13. | 



14.J 



