INTRODUCTION. xlv 



79. Genus Oulangia. 

 Milne Edw. and J. Haime, Comptes rend., t. xxvii, p. 497, 1848. 



Corallum composed of very low, cylindrical corallites, which appear to arise by gem- 

 mation on a basal incrasting expansion, and having their walls naked and costate, as 

 in the preceding genus, but with a highly-developed, papillose columella. Septa very 

 exsert, closely set ; those of the principal cycla having their upper edge almost entire. 



Typ. sp., Oulangia Stokesiana, Milne Edw. and J. Haime, Ann. des Sc. Nat., 3 me se>ie, vol. x, 

 tab. vii, fig. 4. 



Aberrant Group. 

 PSEUD ASTRELDvE. 



Corallum composite, thin, and foliaceous, and increasing by extra-calicular gemmation. 

 Corallites short, well circumscribed, and dispersed on the surface of a common lamellar 

 plate. Coenenchyma echinulate. Septa well developed, very echinulate. Dissepiments not 

 numerous. No synapticulae. Common basal wall imperforate, sub-costulate, and naked. 



Genus Echtnopoea. 



Lamarck, Hist, des An. sans Vert., vol. ii, p. 252, 1816; Echinastrea, Blainville, Diet, des Sc. Nat., 



vol. lx, p. 343, 1830. 



Corallum adherent, near the centre, and expanding into large foliaceous, lobated 

 laminae. Calices circular, with an exsert margin. 



Typ. sp., Echinopora rosularia, Lamarck, loc. cit., p. 253 ; Milne Edw., Atlas du Regne Anim. de 

 Cuvier, Zooph., tab. Ixxxiii ter, fig. 1. 



Transitional Group. 

 PSEUDOFUNGID^E. 



Corallum composite and foliaceous, having a perforated plate or basal wall (as in 

 Fungidae) and interseptal dissepiments (as in Astreidae). Calices forming radiating series, 

 separated by lobes or ridges. No synapticulae. 



Genus Merulina. 



Ehrenberg, Corall. des Rotb. Meeres, p. 104, 1834. Typ. sp., Merulina ampliata, Ebrenberg, loc. cit. 



Family IV. 

 FUNGIDAE. 



Dana, Expl. Exped., Zooph., p. 283, 1846. 



Corallum simple or composite, very short and expanding, so as to constitute a disc 

 or foliaceous lamina. Calice very shallow, and open laterally in simple species ; 



