FAMILIES AND GENEEA OE THE MADEEPOEAllIA. 



171 



centre. Synapticula, both small and large, occupying the 

 place of a corallite-wall, and of that of the eminences also. 

 Gremmation between the calices. 



Distribution. — Hecent. 'Red. Sea, Indian Ocean. 



This diagnosis refers to 3£eandroseris so far as it includes M. 

 JBottcB. 



Group-Genus Mycetar^a, Pratz. 



Genus MrCETARiEA, JPratz, PalcBontographica, xxix. Band, 

 Lieferug 2, p. Ill (1882). 



Corallum simple, or composed of two or more confluent calices, 

 growing in a succession of alternating oval, irregularly trochoid 

 to cylindrical shapes. The young individuals either remain 

 united close to the parent as they grow, or become separated 

 and distinct in the upper portion, forming angular projections. 

 Epitheca exists. Septa projecting, numerous, finely toothed, 

 subequal, and built up of regular series of trabeculje. Inter- 

 trabecular areas slightly or not filled in. Septal laminae united 

 by more or less regular synapticula. 



Distribution. — Fossil. Jurassic : Europe. 



CHAPTER YI. 



The Section Madreporaria Perforata, definition, and families. Family Eu- 

 psammidse, alliances and genera. Family Madreporidffi, alliances and genera. 

 Family Poritidie, alliances and genera. 



III. Section MADREPORAEIA PEEFOHATA, Ed. ^ H. 



This section is thus described in the Hist. Nat. des Corall. 

 vol. iii. p. 88, 1860, and was established in 1850. 



" Corallum entirely or almost entirely composed of porous or 

 reticulate coenenchyma. Septal apparatus well characterized and 

 primitively composed of six elements, but sometimes being repre- 

 sented only by series of trabeculse. Dissepiments rudimentary. 

 Tabulae absent," 



This definition is correct as far as the end of the last sentence 

 but one; but it requires some additions and alterations. 



