XXXVuli BRITISH FOSSIL CORALS. 
54. Genus HypNopHora. 
Fischer de Waldheim, Deserip. du Mus. Démidoff, vol. ui, p. 295, 1810; Monticularia, Lamarck, Hist. des 
Anim. sans Vert., t. ii, p. 248, 1816. 
Corallum formed of irregular series of corallites, united by thew walls, which are thick, 
compact, and constitute ridges, divided longitudinally, so as to represent rows of conical 
prominences, or monticule. The calicular trenches are transversal as well as longitudinal, 
and there is no columella. Sepfa nearly equal, and rising to the apex of the conical mural 
monticula. General form sometimes massive and sub-globose or gibbous; sometimes 
sub-explanate. 
Typ. sp., Hydnophora Demidovii, Fischer, Oryet. du Gouv. de Moscou, pl. xxxii. 
Section II1I.—ASTREIN A) DENDROID &. 
Corallum always increasing by lateral gemmation. The corallites segregate, and having 
an arborescent or fasciculate arrangement. Septa regularly and delicately serrated ; those 
of the principal cycla always bearing pali. 
55. Genus CLADOCORA. 
(In parte) Ehrenberg, Corall. des Roth. Meeres, p. 85, 1834; Caryophyllia, Dana, Zoophytes, p. 378, 1846. 
Corallum arborescent, forming branched clumps. Cora/lites cylindrical, very long, and 
completely free laterally. Calices circular, or almost so. Columella papillose. Pali well 
developed, and corresponding to all the septa, except those of the last cyclum. Sept 
slightly exsert, nearly equal, granulated, and having their apex arched and delicately serrated. 
Walls compact, with simple, granulated, or echinulated coste, and an incomplete epitheca, 
which often expands into circular, horizontal leaves, extending to the neighbouring 
corallites. 
Typ. sp., Cladocora cespitosa, Milne Edw. and J. Haime ; Madrepora flexuosa, Solander and Ellis, tab. 
xxxi, figs. 5, 6. 
56. Genus PLEUROCORA. 
Milne Edw. and J. Haime, Comptes rend. de l’Ac. des Se., t. xxvii, p. 494, 1848. 
Corallum sub-dendroid. Corailites cylindrical, very short ; united by their basal part, 
and free towards their upper end. Columella, pali, and septa much as in the preceding 
genus. Walls compact, extremely thick, and never presenting any traces of an epitheca. 
Coste distinct from one end of the corallites to the other, and vermiculate. 
This genus approximates in some degree to Dendrophyllia and to Oculina. 
Typ. sp., Pleurocora explanata, Milne Edw. and J. Haime, Ann. des Sc. Nat., 5™° série, vol. x, 
tab. vil, fig. 10. 
