::0 BRITISH FOSSIL CORALS 



I. AsTROccENiA RErTANs, Duncau. Plate IV, figs. 4, 5, 6, 15. 



The corallum is short, convex, and very irregular; it is moderately large for an 

 Astrocoenian, and is covered with numerous and closely packed calices. 



Tlie calices are polygonal and shallow, and are separated by very distinct, plain, 

 ccenenchyma, which is obtusely ridged, and prominent here and there. 



The septa arc twenty in number ; ten reaching the columella, and ten joining five of 

 the longer, in pairs. 



The septal arrangement is very marked. 



The columella is small and the costae are rudimentary. 



The length of three calices, with the ccenenchyma, is about Ijths inch. 



Localiiy. The Sutton Stone, Brocastle, and at Ewenny. In the Collection of 

 Charles Moore, Esq., F.G.S., Bath. 



.1. AsTRoccENiA PARASITICA, Duucan. Plate V, tigs. 5, 6. 



The corallum encrusts other Madreporaria, such as dendroid Astraeaceae or "remaiiie 

 Lithostrotions ; it is small and short, and possesses much ccenenchyma. 

 The caHces arc very small, distant, and shallow. 

 The septa appear to be ten in number. 

 The columella is well mai'ked. 

 The ccenenchyma is plain. 

 The diameter of the calices is about ;i'„th inch. 

 Locality. The Sutton Stone. In the Museum of Practical Geology, London. 



(5. AsTROccENiA PEUUNCULATA, Duncaii. Plate V, figs. 7, 8, 9. 



The corallum is small, pedunculate, and fungiform ; it has an epitheca and much 

 ccenenchyma. 



The peduncle is short, small, and rounded, and joins the expanded discoid epithecate 

 base of the true corallum near its centre. 



The discoid base has an epitheca, and its edges are slightly rounded. 



The convex upper part of the corallum is covered with unequal, shallow, and distant 

 caHces. 



The calices are irregular in size, and are small. 



The septa are small, alternately long and short, and are granulated laterally. Theie 

 are twenty of them, and the smallest are rudimentary. 



