Ixii BRITISH FOSSIL CORALS. 



8. Genus Halysites. 



Fischer, Zoognosia, 3d edit., vol. i, p. 387, 1813; Catenipora, Lamarck, Hist, des An. sans Vert., t. ii, 



p. 206, 1816. 



Corallites extremely long, arranged in a single series, and united laterally, so as to 

 constitute large flabelliform expansions, which remain free laterally, but often meet, and 

 thus form a lacunous mass. Epitheca very thick. Septa almost rudimentary, but very 

 distinct in perfect specimens. Tabid a horizontal. 



Typ. sp., Hah/sites escharoides, Fischer; Catenipora escharoides, Lamarck, loc. cit., p. 207. 



9. Genus Harmodites. 



Fischer. Notice surles Tubipores fossiles, 1828; Syrwgopora, Goldfuss, Petref. Germ., vol. i, p. 7o, 1826-33. 



Corallum fasciculate. Corallites irregularly cylindrical, very long, and united by hori- 

 zontal connecting tubes. Tabulce infundibuliforai. 



Typ. sp., Harmodites raitnrlosa, nob. ; Syringopora ranndosa, Goldfuss, loc. cit., pi. xxv, fig. 7. 



10. Genus Thecostegites. 

 Milne Edw. and J. Haime, Comptes rend., t. xxix, p. 261, 1849. 



Corallites cylindrical, short, and united by strong mural expansions situated at various 

 ights. Tabid cb horizontal. 



Typ. sp., Thecostegites Bouchardi, nob.; Harmodites Bouchardi, Michelin, Icon. Zooph., pi. xlviii, fig. 3. 



Fourth Tribe— POCILLOPOMNJE. 



Corallum massive, gibbous, or subdendroid, with thick imperforated walls, forming, 

 towards the surface, an abundant compact cceneuchyma. Septa quite rudimentary. 



II. Genus Pocillopora. 

 (Pa?-s) Lamarck, Hist, des An. sans Vert., t. ii, p. 273, 1816; Dana, Zooph., p. 523, 1846. 



Calices shallow, and presenting, at their bottom, a transverse, thick, projecting ring, 

 resembling a columella. 



Typ. sp., Bocillopora acuta, Lamarck, loc. cit., p. 274 ; Mine Edw., Atlas du Regne Animal de Cuvier, 

 Zooph., pi. lxxxi, fig. 3. 



