INTRODUCTION. xxxv 



44. Genus Tridacophyllia. 



Blainville, Diet, des Sc. Nat., vol. lx, p. 327, 1830. 



Corallum short, and composed of corallites, arranged in series intimately united by their 

 lateral walls, which, instead of forming a simple ridge as in the preceding genera, constitute 

 very tall, foliaceous expansions, variously twisted, and terminated by a sub-crenulate margin ; 

 the calicular trenches broad, very deep, and winding. Columella quite rudimentary, but the 

 calicular centres very distinct. Septa projecting very little, thin, nearly equal, and serrate. 

 Dissepiments abundant, very oblique, convex, and forming long vesicules. Plate or exterior 

 surface of the common wall of the corallum covered with lamellar costse, which extend from 

 the basis of the mass, project slightly, and are irregularly denticulate. 



Typ. sp., Tridacophyllia lactuca, Blainville, loc. cit. ; Concha fungiforrnis, Seba, Thes., v. iii, tab. exxxix, 

 No. 10; Pavonia lactuca, Lamarck, An. sans Vert., vol. ii, p. 239 ; Manicina lactuca, Ehrenberg, op. cit., p. 103. 



45. Genus Trachyphyllia. 



Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 492, 1848. 



Corallum short, increasing by fissiparity, and composed of very flexuous series of coral- 

 lites, free laterally. Common walls strongly echinulate. Epitlieca rudimentary. Columella 

 well developed, but of a very loose, spongy texture. Septa numerous, crowded, exsert, and 

 strongly granulated laterally. 



Typ. sp., Trachyphyllia amarantum, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3 me ser., vol. xi, 

 p. 275 ; Amarantum saxum, &c. Rumph. Amb. Hort. vi, tab. lxxxvii, fig. 1. 



46. Genus Aspidiscus. 



Konig, Icon. Foss. Sect., p. 1, 1825 ; Cyclophyllia, Milne Edw. and J. Haime, Comptes rend, de l'Acad. 



des Sc, vol. xxvii, p. 492, 1848. 



Corallum discoidal, with its inferior surface flat, and its upper surface convex. Corallites 

 arranged in radiating series, separated by thick and simple, crest-like mural ridges, excepting 

 towards the margin of the calicular surface, where the young individuals spread out so as to 

 form a broad, continuous, lamello-striate border. Columella rudimentary, but the calicules 

 well individualized. Septa very thin and crowded, but not numerous in each corallite. 

 common plate covered with a thick epitheca, presenting concentric striae or folds. 



Typ. sp., Aspidiscus cristatus, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3 rae serie, vol. xi, p. 277 ; 

 Aspidiscus Shawi, Kbnig, Icon. Foss. Sect., pi. i, fig. 6; Cyclolites cristata, Lamarck, Anim. sans Vert., 

 t. ii, p. 234. 



47. Genus Scapophyllia. 



MUne Edw. and J. Haime, Comptes rend, de l'Acad. des Sc, t. xxvii, p. 492, 1848. 



Corallum columnar, erect, very dense, and formed of corallites arranged in series, 

 completely united laterally. Columella tubercular, somewhat compact. Septa very thick, 

 neither closely set nor numerous ; with their sides very echinulate, and the apex denticulate. 

 Dissepiments simple and distant. 



Typ. sp., Scapophyllia cylindrica, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3"" serie, vol. x, 

 tab. viii, fig. 8. 



