FROM THE ZONE OF AMMONITES ANGULATUS. 29 



3. Ctathoccenia costata, Duncan. PI. V, figs. 10, 11. 



The corallum is flat, and presents slightly rounded eminences ; it is short, and has an 

 irregular base where it is attached to foreign bodies. 



The calices are numerous, nearly equal, and distant. The margins of the calices 

 are flat, and are continuous externally with the coenenchyma, whose upper surface is 

 covered by the costae. 



The calicular fossae are deep. 



The septa are small, unequal as regards length, but rather equal in their thickness ; 

 they vary in number from twenty to twenty-four. 



There is no columella. 



The costge are large, slightly rounded, not continuous, and occasionally slightly wavy. 



Three calices occupy a length of ^Iths inch. 



Locality. Brocastle. 



In the Collection of Charles Moore, Esq., F.G.S., Bath. 



Genm — Elysastr^a.'^ 



1. ELYSASTRiEA FiscHERi, Laube? PL VI, figs. 5 — 9. 



The corallum is massive; the corallites are close and united above and near the calices, 

 but separate and more or less covered with epitheca below. 



The corallites are unequal in size, tall, and more or less cylindrical below and 

 polygonal above. 



The calices are very variable in shape and size, and the margin is broad and distinct. 



The septa are numerous, often wavy, unequal in length, and near to the centre of 

 the calice a new set appears to come in, in some calices. There are no pali. 



The number of septa depends upon the size of the calice, and it may vary from 

 forty to sixty. 



The septal laminae are thin, and faint traces of costae may be seen where the walls 

 are not fused together. 



The gemmation is extra-calicular, but the bud probably springs from the centre of 

 a corallite, and works its way outwards. 



The columella is rudimentary. 



Diameter of calices, ^ths to #hs inch. 



Locality. The Sutton Stone. The St. Cassian beds. 



In the Museum of Practical Geology, London. 



1 Laube, op. cit., and ' Intro. Brit. Foss. Corals,' 2nd series, part i. 



2 Laube, op. cit. 



