FROM THE OOLITIC STRATA. 15 



The base of the calicular fossa is formed by a broad tabulate dissepiment. 

 Diameter of the calices -^th to -g-th inch. 

 Locality. Great Oolite, Cirencester. 

 In the Collection of T. C. Brown, Esq. 



3. Cyathophora tuberosa, Duncan. PI. Ill, figs. 15 — 18. 



The corallum is tuberose, and the base is contracted and small. 



The corallites are numerous, not crowded, unequal, and are separated by much 

 exotheca. 



The calices are circular, slightly crateriform, and raised, and the primary septa 

 encroach upon the central space, which is shallow. 



The costse are unequal and long, and the calicular wall projects between the primary 

 and secondary septa to produce tertiary costae, which have no corresponding septa. 



The septa are unequal, and there are six systems and two cycles. 



Height of corallum 1^ inch. Breadth of calices i^th inch. 



Locality. Great Oolite, Cirencester. 



In the Collection of T. C. Brown, Esq. 



Genus — Isastr^a. 

 4. Isastr^a gibbosa, Duncan. PI. II, figs. 10, 11. 



The corallum is gibbous, and the corallites are excessively crowded. 



The calices are depressed, irregular in shape, and have a broad margin, and art- 

 shallow. 



The septa are sub-equal, crowded, short, and marked with lateral ornamentation of a 

 moniliform character. There are six systems and three cycles. 



The central fossa is encroached upon by the larger septa, which do not meet with 

 their central margins. 



Diameter of largest calices ^th inch. 



Locality. Great Oolite, Cirencester. 



In the Collection of T. C. Brown, Esq. 



