106 PEOF. p. MAETIN DUKCADf'S I^VISIOTiT OF THE 



degree. Costse continuous with the septa, parsing over the outer 

 surface of the wall, rarely confluent. A marked depression between 

 the corallites. Endotheca exists. Epitheca often in bands. 

 The young colony consists of a few corallites comparatively 

 without union, except by the base of the beds. 



Distribution. — Fossil. Eocene : Europe. 



This genus supersedes AgatTiiphyllia, Eeuss. 



Grenus Phtmastejea, Milne-Edwards Sf Jules Haime, JBCist. Nat. 

 des Corall. vol. ii. p. 499 (1857), amended; Duncan, Proc. 

 Zool. Sac. 1883, p. 408 (June 19). 



Syn. Amphiastrcea, Etallon. 



Colony massive, tall or very short, with a convex or plane free 

 surface. Corallites more or less prismatic, increase by extracali- 

 cular gemmation, and are joined together by short growths from 

 costse or from the wall, which are placed with some regularity in 

 vertical series ; elsewhere they are separate. An epitheca exists, 

 which may environ the growths. Calices separate, unsymmetrical. 

 Columella present. Septa variable in number, dentated. Costse 

 may or may not be apparent. 



Distribution. — Fossil. Jura: Europe. — Mecent. Indian Ocean ; 

 Mergui. 



M. Etallon described the genus Amphiastrcea in 1858, and M. 

 de Eromentel introduced it in his 'Introd. a 1' etude des Polyp, 

 foss. ; ' but neither had studied the recent fauna ; had they done so 

 they would have found their fossil form to be of the same genus 

 as PhymastrcBa, Ed. & H., 1848. Amphiastrcea is absorbed. 



Klunzinger, in his excellent wort on the Corals of the Red 

 Sea, unites the genera Gyphastrcea and Solenastrcea of Milne- 

 Edwards and Jules Haime. Cyphastrcea, Ed. & H., has all the 

 characters of Solenastrcea, and in addition the septal laminge are 

 perforate, trabeculate, and cribriform, except close to the wall, 

 where they are solid. Some modern Solenastrseans have this 

 character, and hence the proposed union. The fossil Oyphastrcea 

 costata, nobis, of the "West-Indian Miocene has exceedingly 

 cribriform septa, so that the distinction is not modern. The 

 character has nothing to do with fossilization or with wearing, and 

 it is general over the whole of the corallites of the species. But 

 some fossil Solenastrseans have solid, non-cribriform septa. 

 There is not a generic distinction between the two forms ; but 

 Gyphastrcea, which is more recent than Solenastrcea, had better 

 become a subgenus. 



