SUBCLASS ir 



HEXACORALLA 



101 



Fig. 155. 



Astrocoenia decaphylln E. aiul H. Upper Cretaceous ; Gosau 

 Valley, Austria, a, Corallum, natural size ; 6, Calices enlarged. 



Flacocoenia d'Orb. ; Crijptocoenia E. and H. Jurassic and Cretaceous. 



Cyathophora Mich. Massive colonies, with corallites united by costae. 

 Septa short, not reaching the centre ; columella absent. Visceral chamber 

 partitioned otf by horizontal 

 tabulae. Jurassic and Cre- 

 taceous. 



Coccophyllum Eeuss. Massive 

 colonies, with corallites united 

 directly by their walls. Calices 

 polygonal, septa numerous. Col- 

 umella absent ; visceral cham- 

 ber tabulated. Alpine Trias. 



Pinacophyllum Freeh. Tri- 

 assic. 



Holocystis Lonsd. Massive colonies, with corallites united by costae. Four 

 of the septa larger or stouter than the rest. Tabulae in visceral chamber. 

 Cretaceous. 



Astrocoenia E. and H. (Fig. 155). Massive colonies. Corallites polygonal, 

 united by their walls ; septa numerous, long. Columella styliform ; only 

 dissepiments present in visceral chamber. Trias to Tertiaiy. 



Stephanocoenia E. and H. Like the preceding, but with columella 

 surrounded by cycle of pali. Trias to Recent. 



Fhyllocoenia E. and H. {Confusastrea d'Orb. ; Adelastrea Reuss). Massive 

 colonies. Corallites round or oval, imperfectly united by costae. Septa 

 strongly developed, thickened in the middle between theca and the centre. 

 Columella rudimentary. Trias to Tertiary. 



Convexasfrea d'Orb. Trias to Cre- 

 taceous. Columnastrea, Stylocoenia E. 



Cretaceous and Tertiary. 



and H., etc. 



7- 



Corolla multiplying by fission. 



Fig. 156. 



Plomphyllia calycidata Eeuss. Oligocene ; Monte 

 Carlotta, near Vicenza. Natural size. 



Haplosmilia d'Orb. Bushy colonies. 

 Corallites usually with dichotomously 

 dividing crests. Calices circular or 

 elongated ; columella styliform ; theca 

 with ridge-like costae. Jurassic. 



Plocophyllia Reuss (Fig. 156). 



Branching, foliaceous, or massive 



colonies. Corallites either becoming 



free or grouped into detached rows. 



Columella absent. Tertiary. 



Barysmilia E. and H. Corallum massive, forming a thick stem, the apex 



of which is covered with short buds. Calices oval, sometimes disposed in 



series ; columella rudimentary. Cretaceous. 



Stenosmilia From. Like the preceding, but with lamellar columella. 

 Cretaceous. 



Fachygyra E. and H. Corallites arranged in winding rows, and united by 

 a broad mass of costal coenenchyma. Columella lamellar. Jurassic and 

 Cretaceous. 



