ON THE BRITISH FOSSIL CORALS. 



135 



With ccenenchyma . . 

 Without coenenchyma 



Section TABULATA. 



Families. 



J MiUeporidce, Coenenchyma cellular. 



[ Acroporklce. Ccenenchj^ma compact. 



(Favositidce. Walls perforated. 



Halysitidce. Walls imperforate. 



Alveolitidce. Septa trideutate. 



Genera. 

 CMillepora*. 

 j Heliolites, Hellopora-f, Pohjtremacis. 



MiLLEPOEiD^ J P'-^^^r''^ P^asmopora, Thecia. 



I Lyelha. 

 I Thecostegites, 

 '^Axopora. 

 1 i -^cro2Jom, Seiiatopora, PocillojJOra, DendrojJora, Bhah- 



\ dopora. 



( Favosites, Koninchia, Favosltipora, genus nov. (Kent). 

 I Mklielinia, Scemeria, Emmonsia. 

 ■^1 Syringopora. 

 \^ Aulop)ora. 

 '' Halysites. 

 Stylopliyllum. 

 Conostegites. 

 Columnaria. 

 Beaumontia. 

 j Alveolites. 

 \ Ccenites. 



T . J- f Fistidipora. 



Incerttc sedis \ m ^ i • 



\ Fletchena. 



Fayositid^ 



Halysitid^ ■( 



AxTBOlIXIDiE 



Alcyoxakta. 

 Chcetetes. Montladipora. Dania. 



ora. 



Lahechia. 



TV. The Eugosa. — Mil. Miliic-Edwards and Jules Haime observe (op>. cit. 

 vol. iii. p. 323), "'that this division comprehends simple and compound 

 corals, and that the septal apparatus never forms six distinct systems, and 

 appears to be derived from four primitive elements. Sometimes this dispo- 

 sition is shown by the great development of four principal septa, or by the 

 existence of four depressions which occupy the bottom of the calice and 

 take on a cross-like look. In other instances there is observed only one of 

 these depressions or excavations, or one large septum interferes Avith the 

 regularly radiate and star-shape of the septal arrangement. Finally, there 

 arc instances where no traces of distinct groups or systems of sejita can be 

 recognized, and where the septa are represented by numerous stria; arising 

 on the upper surface of the tabulaj or dissepiments near the calicular mar- 

 gin." They continue as follows : — " The corallites are always perfectly di- 

 stinct amongst themselves, and are never united by independent coenenchyma. 

 The walls are in general very slightly developed. The visceral chamber is 



* MiUcpora is a most aberrant genus if it is one of the Madreporaria Tabulata. I have 

 not yet satisfied myseK about the Hydroidean characteristics of its soft parts ; but an 

 examination of the coenenchyma of a series of species throws great doubt upon the Ma- 

 dreporarian affinities. 



t The relation of ReU<ypora to Heliolites is of the closest. 



