246 



ACTINOZOA. 



MontlivauUia are especially rich in species. 

 Two generic forms represent the Perforata. 

 The families Titrbinolidce and Oculinidce now 

 appear for the first time. The following genera 

 are exclusively Jurassic : 



TuRBINOLIDvE. 



Biscocyatlnis, 

 Thecocyathus. 



OCULINID^. 



Euhdia. 



ASTR^ID^. 



Axos7mIia. 



Haplosmilia. 



Pkytogyra. 



ASTR^ID^ : 



PlacosphyUia. 

 AngeastrcBa. 



Protoseris. 

 Comoseris. 



POEITIDJE. 



Microsolena. 

 Anomophyllum. 



II. Cretaceous Corals. — 



The Corals of the Chalk are very numerous, 

 belonging chiefly to the Ajporosa and Perforata. 

 Here also undoubted indications of Alcyonaria 

 present themselves. The Tahulata are repre- 

 sented by two genera. For the last time the 

 order Pugosa makes its appearance, a single 

 genus, Holocystis, being its representative. The 

 families MadreporidcB, Pennatulidce (?), and Gor- 

 f/onidoi (?) now first appear. The following genera 

 are peculiar to this period : 



TURBINOLIDJE. 



Brachycyathtts 

 Cyclocyathus. 

 Stylocyathus. 

 Smilotrochus. 



OCULINID^. 



Synhclia. 

 Baryhclia. 



ASTR/EID^. 



Placosmilia. 

 Dipfoctenium. 

 ParasDiilia. 

 Pej)losmilia. 



AsruMTDM : 

 Holocmnia. 

 Acanthoccenia. 

 Placocoenia. 

 Elas7noc(xnia. 

 Pentacoenia. 

 Heterocoenia. 

 Leptophyllia. 

 Bactylosmilia. 

 Hymenophyllia. 

 Aspidiscus. 

 Stelloria. 

 Meandrastrcea. 



