FAMILIES AND GENERA OP THE MADEEPORABIA. 121 



united by their walls and by more or less ccenencbyma, polygonal, 

 and often cylindrical. Calices small. Columella absent. Septa 

 finely dentate. Costse not confluent. Gremmation superior and 

 marginal. 



Distribution. — Fossil. Infra- Lias : England. 



The presence of structure between tbe walls is decided ; but 

 it is very slight, and not sufficient, considering the otber cha- 

 racters, to remove the genus out of this Alliance. The nature 

 of the calicinal walls and the irregular septal distribution of the 

 genera Aplocoenia and Pentaco&nia distinguish them from the 

 above. The genus is distinct from Koilocoenia. 



Grenus Stephanoc(ekia, Milne-Edwards Sf Jules Saime, Hist. 

 Nat. des Oorall. vol. ii. p. 264 (1857). 



Syn. Stepharuistrcea, Etallon, 1864. 



Colony massive, convex, lobed, or pedunculate, or incrusting 

 or dendroid. Corallites united by their walls, which are compact 

 and thick. Calices generally polygonal, with simple margins. 

 The columella is styliform and slightly projecting, but always 

 well developed. The septa are slightly exsert, denticulate slightly, 

 well developed, granular at the sides. There are pali before all 

 the septa except those of the last cycle. Gremmation marginal 

 and lateral. 



Distribution. — Fossil. Jurassic : Europe. Cretaceous : Europe 

 and England. Eocene : Europe. Eocene and Miocene : Sind, 

 Asia, West Indies. — Recent. Locality ? 



Genus Naecissaste^a, E. Pratz, Eocene Korallen aus der 

 LibyscTien Wuste und Aegypten (1883), p. 228. 



Colony massive, composed of long, polygonal corallites united 

 by their walls, without costse and coenenchyma. Calices more or 

 less deep. Septa toothed. Pali in one crown. Columella ? 

 Dissepiments abundant. 



Distribution. — Fossil. Eocene : N.E. Africa. 



The genus will be better understood when other types of it 

 are found. It is allied to Stephanocoenia. 



Tribe II. 



Grenus Haldonia, Duncan, Quart. Journ. Geol. Soc. 



vol. XXXV. (1879), p. 91. 



Colony massive, incrusting, convex above. Corallites united 



by their walls. Calices small, circular in outline, raised, deep, 



and widely open, separated by a slight depression. Columella 



