84 COELENTERATA CX1DARIA SUB-BRANCH n 



Flabellum, Lesson. (Fig. 133). Wedge-shaped, compressed, isolated, or 

 attached. Septa numerous. Wall covered with epitheca, and sometimes 

 furnished with spinous processes. Tertiary and Recent. 



Trochocyathus, E. and H. (Fig. 134). Horn-shaped, with circular calice. 

 Septa stout; columella papillous and trabecular, and surrounded by several 

 cycles of pali. Numerous species from Lias to Recent. 



Thecocyathus, E. and H. Depressed, conical, or discoidal, attached early in 

 life, later becoming free. Wall with thick epithecal investment. Calice 

 circular, septa numerous ; columella fasciculate, and surrounded by several 

 cycles of pali. Lias, Jurassic, Cretaceous, and Recent. 



Paracyathus, Deltocyathus, E. and H. Tertiary and Recent. Discocyathus, 

 E. and H. Jurassic. Coenocyathus, Acanthocyathus, Bathycyathus, E. and H., etc. 

 Tertiary and Recent. 



Caryophyllia, Stokes (Fig. 136). Turbinate, with broad base, attached. 

 Calice circular; columella papillous, trabecular, and surrounded by a single 

 cycle of pali. Cretaceous to Recent. 



Family 2. Oculinidae. Milne-Edwards and Haime. 



composite corolla, increasing by lateral gemmation. Walls of corallites 

 thickened by a compact coenenchyma. Lower portion of visceral chamber narroived 

 or filled up by deposition of stereoplasma. Septa moderately numerous ; interseptal 

 loculi usually open to the base. Lias to Recent; fossil forms not particularly 

 numerous. 



Oculina, Lam. Corallites irregularly or spirally distributed over the smooth 

 surface of coenenchyma. Septa slightly projecting; columella papillous, 

 surrounded by cycle of pali. Tertiary and Recent. 



Agathelia, Reuss. Like the preceding, but form- 

 ing tuberous or lobate colonies. Cretaceous and 

 Tertiary. 



Synhelia, E. and H. Cretaceous. Astrohelia, E. 

 and H. Tertiary. Psammohelia, Euhelia, E. and H., 

 etc. Jurassic. 



Haplohelia, Reuss. Small, arborescent, with 

 corallites all disposed on one side of the branches. 

 Coenenchyma striated or granulated. Septa in 

 tnree cycles ; columella and pali present. Oligocene. 

 Enallohelia, E. and H. (Fig. 137). Stock 

 branching ; corallites disposed usually in alternating 

 sequence in two rows along the sides of branches. Coenenchyma highly 

 developed, striated, or granulated ; columella rudimentary. Jurassic. 



Family 3. Pocilloporidae. Verrill. 



Composite, branching, lobate, or massive colonies, with small cylindrical corallites, 

 united by compact coenenchyma. Septa few (6-24), sometimes rudimentary. Visceral 

 chamber partitioned off by horizontal tabulae. 



Of the two recent genera belonging to this family, Pocillopora and Seriato- 

 pora, Lam., the former occurs also fossil in the Tertiary. 



