lxxvi BRITISH FOSSIL CORALS. 



4. Genus Sarcodictyon. 



E. Forbes ap. Johnston, Brit. Zooph., 2d ed., p. 179. 



Polypi rising from creeping, filiform, anastomosing stolons, distant, uniserial, and 

 appearing verruciform (not tubular) when retracted. Differ from Cornularia by the short- 

 ness of the polypidoms. 



Typ. sp., Sarcodictyon catenatum, Forbes, loc. cit., tab. xxxiii, figs. 4, 7. 



5. Genus Anthelia. 



Savigny, ap. Lamarck, An. sans Verteb., vol. ii, p. 407, 1816. 



Polypi not retractile, and rising from a thin fleshy incrustating plate. 

 Typ. sp., Anthelia glauca, Savigny, Egypte, Polypes, tab. i, fig. 7. 



6. Genus Sympodium. 

 Ehrenberg, Corall., p. 61, 1834. 



Polypi resembling Anthelia, but being retractile. 



Typ. sp., Sympodium fuliginosum, Ehrenb., Savigny, Egypte, Polypes, tab. i, fig. 6. 



7. Genus Aulopora. 



Goldfuss, Petref. Germ., vol. i, p. 82. 



The fossil corals forming this genus greatly resemble Cornularia and Sarcodictyon, but 

 differ from all the preceding genera by their thick, calcareous polypidom. 



Typ. sp., Aulopora serpens, Goldfuss, loc. cit., tab. xxix, fig. 1. 



8. Genus Cladochonus. 



M'Coy, in Ann. and Mag. of Nat. Hist. 1st series, vol. xx, p. 227. 



Corallum resembling Aulopora, but composed of cup-shaped calices, arranged in a 

 regularly alternate manner, and bent in nearly opposite directions. 



Typ. sp., Cladochonus tenuicollis, M'Coy, loc. cit., tab. xi. fig. 8. 



