lxviii BRITISH FOSSIL CORALS. 



12. Genus Cyathophyllum. 



Goldfuss (in parte), Petref. Germ., vol. i, p. 54, 1826. 



Corallum simple or composite. No costa. Septa well developed, extending to the 

 centre of the calice, and twisted together so as to produce the appearance of a small colu- 

 mella. Tabula occupying only the centre of the visceral chamber ; the outer portion of 

 which is filled up with numerous vesicular dissepiments. A single wall, situated exteriorly, 

 and provided with a complete epitheca. 



Typ. sp., Cyathophyllum helianthoides, Goldfuss, loc. cit., tab. xx, fig. 2. 



13. Genus Pachyphyllum. 



Corallum composite, and increasing by lateral gemmation. Corallites united in their 

 lower portion by means of the great development of the costse and the exotheca, and not 

 delimitated by an individual epitheca. Tabula well characterised. 



Typ. sp., Pachyphyllum Bouchardi, nob. 



14. Genus Campophyllum. 



Corallum simple, very tall, and protected by an epitheca. Septa well developed. 

 Tabula very large, and smooth towards the centre. Interseptal loculi filled with small 

 vesiculse. 



Typ. sp., Campophyllum fiexuosum ; Cyathophyllum flexuosum, Goldfuss, Petref. Germ., vol. i, tab. xvii, 

 fig. 3. 



15. Genus Streptelasma. 

 Hall, Palseont. of New York, p. 17, 1847. 



Corallum simple, and differing from Cyathophyllum by the structure of the wall, which 

 is destitute of epitheca, and covered with sublamellar costae. 



Typ. sp., Streptelasma comiculum, Hall, loc. cit., tab. xxv, fig. 1. 



16. Genus Oaiphyma. 



Rafinesque and Cl'fford, in Ann. des Sc. Pbys. de Bruxelles, vol. v, p. 234, 1820. 



Corallum simple, turbinate. Wall provided with a rudimentary epitheca, and pro- 

 ducing radiciform appendices. Septa very numerous, equally developed, and divided into 

 four groups by an equal number of shallow septal fossuiae. Tabula well developed, and 

 smooth towards the centre. 



Typ. sp., Omphyma turbinata ; Madrepora turbinata, Lin. Anicen. Acad., vol. i, tab, iv, fig. 2. 



