156 PBOF. p. MABTIN DUNCAJir's EEYISION OF THE 



three cycles and part of the fourth. Synapticula rare. Colu- 

 mella fasciculate, vermiculate, and distinct. 



The delineation of the species is a mere sketch ; but it shows 

 that the calices are close and separated by a mere ridge, over 

 which, from the description, we may presume the septa are con- 

 fluent with their neighbours. The calices are deepish. 



Now in the species noticed by De Promentel the calices are also 

 deep ; the septa are confluent and in bundles. Neither Btallon 

 nor De Fromentel writes anything about the structure of the 

 septa, whether they are perforate or merely trabeculate or solid. 



Etallon lays stress on the fact that there are no dissepiments 

 between the septa. 



The generic diagnosis might now be stated as : — 



Colony variable in shape, amorphous and convex, turbinate and 

 conical, or in lamellse. Corallites low and small, polygonal, close. 

 Calices rather deep, polygonal, separated by narrow margins, over 

 which the septa pass. Columella fasciculate and papillary, fused. 

 Septa in three or four incomplete cycles, well- developed, often 

 uniting, thickish, but diminishing in width in the higher orders, 

 granulate on the free edge and on the flanks; close. Synapticula 

 small, variable in number. Dissepiments wanting. Epitheca 

 exists ; and it and the colony may be marked with growth-rings. 



Distribution. — Fossil, Jurassic : Europe. 



II. Alliance PAVONIOIDA. 



Colonial Lophoseridse in thiu, frondiform, curled, adherent laminae, 

 crested or not. With an imperfect or synapticulate calicular wall. 

 Calices numerous, distinct or indistinct; on one or on both sides of 

 the fronds. Collines or crest-like ridges exist. Septa occasionally more 

 or less trabeculate and perforate, or solid. 

 Genus Lophosekis, Ed. & H. 

 Genus Tichoseris, Quelch. 

 Genus Mycedium, Oken. 

 Genus Phyllastr^a, Dana. 

 Genus Trachypora, Verrill. 

 Genus Leptoseris, Ed. & H. 



Subgenus Haloseris, Ed. & H. 

 Genus Protoseris, Ed. & H. 



Subgenus Phylloseris, Tomes. 

 Genera absorbed : — 



Pavonia, Lamarck ; Echinophyllia, Klunzinger. 



Phylloseris, Tomes, and Haloseris, Ed. 85 H., become subgenera. 



