xx BRITISH FOSSIL CORALS. 



3. Genus Cyathelia. 



Milne Edw. and J. Haime, loc. cit., p. 68, 1849. 



Corallum arborescent ; gemmation terminal and regularly opposite. Corattites free to a 

 considerable distance from the calice, which are grouped in a way similar to that of flowers 

 constituting a dichotomous cyme. Columella large and papillose. Pali well developed. 

 Septa entire, exsert, and strongly granulated. 



Typ. sp., Cyathelia axillaris, nob. ; Madrepora axillaris, Ellis and Solander, tab. xiii, fig. 5. 



4. Genus Astrhelia. 



Milne Edw. and J. Haime, loc. cit., p. 68, 1849. 



Corallum in general arborescent, and resembling Oculina by its form and its mode of 

 gemmation, but differing from the three preceding genera by the non-existence of pali. 

 Calice with a deep central fossula. Columella septal ; edges of the septa denticulated. 



Typ. sp., Astrhelia palmata, nob.; Madrepora palmata, Goldfuss, tab. xxv, fig, 6. 



5. Genus Synhelia. 



Milne Edw. and J. Haime, loc. cit., p. 68, 1849. 



Corallum arborescent, with thick branches ; gemmation irregular. Calices very shallow, 

 their border scarcely projecting above the surface of the ccenenchyma, and united by com- 

 mon striae. Columella compact, styliform, and terminated by a small tubercle. Septa 

 scarcely exsert. 



Typ. sp., Synhelia gibbosa, nob. ; Lithodendron gibbosum, Goldfuss, op. cit., tab. xxxvii, fig. 9. 



6. Genus Acrhelia. 



Milne Edw. and J. Haime, op. cit., p. 69, 1849. 



Corallum arborescent, or forming a ramified cluster ; gemmation pretty regularly spiral. 

 Surface of the ccenenchyma smooth, excepting in the immediate vicinity of the calices, where 

 slight traces of radiating costse are perceptible. Septa extremely exsert, lanceolate, and 

 entire ; the principal ones uniting towards the lower part of their inner edge, without there 

 being either a columella or pali in the centre of the visceral chamber. 



Typ. sp., Acrhelia Sebce, Milne Edw. and J. Haime, loc. cit., p. 69 ; Seba, Thes., vol. iii, tab. cxvii, fig. 5. 



7. Genus Lophelia. 



Milne Edw. and J. Haime, loc. cit., p. 69, 1849. 



Corallum arborescent, segregate, with coalescent branches ; no true ccenenchyma, but 

 walls very thick ; gemmation irregularly alternate and subterminal. Calices with a reverted 

 lamellar border. Septa entire, exsert, and uniting at the bottom of the visceral chamber as 

 in the preceding genus. No columella nor pali. 



Typ. sp., Lophelia proli/era, nob. ; Ellis and Sol., tab. xxxii, fig. 2 ; Oculina prolifera, Lamarck, An. 

 sans Vert., vol. ii, p. 286. 



