120 



PKOE. P. MAETIN DUNOAI^^'S EEVISIOIS^ OF THE 



tteca greatly developed. Epitheca complete. G-emmation sub- 

 marginal and marginal. 



Distribution. — Subfossil. Eed Sea. — Recent. Eed Sea, Indian 

 Ocean, Pacific. 



X. Alliance ASTROCCENIOIDA. 



Agglomerate Astrseidse, increasing by extracalicular, marginal, and lateral 

 gemmation. Columella variable. Pali may or may not exist. Corallites 

 united by their walls, with sometimes a coenenchymal development. Septa 

 denticulate or entire. 



Tribe I. With denticulate septa. 

 Genus Astroccenia, Ed. & H. 

 Genus Cyathoccenia, Duncan. 

 Genus Stephanoccenia, Ed. & H. 

 Genus Narcissastr^a, E. Pratz. 



Tribe II. With entire septa. 



Genus Styloccenia, Ed. & H. 



Genus Haldonia, Duncan. 

 Genera absorbed: — Ccenastr^a, Etallon; Stephanas- 



TR^A, Etallon. 

 Genus described and not placed: — Bath ycceni a. Tomes, 



probably = Styloccenia. 



Tribe I. 



Genus Astroccenia, Milne-Edivards Sf Jules Haime, Hist. Nat, 

 des Gorall. vol. ii. p. 254, amended. 

 Syn. Coenastrcda, Etallon (1864). 



Colony variable in shape, massive, gibbous, lamellar, dendroid 

 or discoid, compact, sometimes incrusting. Corallites prismatic 

 or cylindrical, uniting by their walls, which are thick and simple ; 

 ccenenchyma rare between them. The calices are polygonal, 

 irregular or regular in shape and size, and their margins are 

 ordinarily simple. The columella is styliform and more or less 

 projecting. The septa are dentated minutely, few in number, and 

 often irregular in their cyclical arrangement. Gemmation mar- 

 ginal and lateral, or marginal and circumferential only. 



Distribution. — Fossil. Trias : Europe. Infra-Lias : England 

 and Europe. Lias, Oolite : Europe, England ? Cretaceous, 

 Eocene : England and Europe, Asia. Eocene : Borneo. Mio- 

 cene : Europe, West Indies ; Sind, Asia. — Recent. Caribbean Sea. 



Genus Ctathoccei^ia, Duncan^ Brit. Foss. Corah (Zone of Amm, 

 angulatus), Pal. Soc. Lond. 1867, pt. iv. no. 1, p. 27. 

 Colony fasciculate or gibbous, or incrusting. Corallites 



