FAMILIES ATfD GENERA OF THE MADREPORARTA. 



187 



Genus Protar^a, Ed. & H. 



Genus Alveopora, Quoy et Gaimard. 



Subgenus Favositipora, S. Kent. 

 Genus Somphophora, Lindstrom. 

 Genus Dichor^a, T. Woods. 

 Genera absorbed : — Stylar^a, Ed. & H.; non Seebach ; Me- 



ANDRAR^A, EtalloU. 



Favositipora, S. Kent, becomes a subgenus ; Koninckia, 

 Ed. & H., a doubtful genus. 



Genera removed : — Microsolena, Lamour. ; Cosctnar^a, Ed. 

 & H. ; DiCTYOPHYLLiA, Blaiuville ; Pleurodictyum, Gold- 

 fuss ; HoLARiEA, Ed. & H. ; Ccenostroma, Winchell. 



G-enus Porites, Milne-Edwards Sf Jules Saime, Hist. Nat. des 

 Corall. vol. iii. p. 173, altered. 



Colony ramifying, or in tufts, or foliaceous, often massive, and 

 lobed or low, incrusting or not. A basal epitbeca invariable in 

 the last instance, frequent in all. Corallites with trabeculate and 

 perforate walls, not distinct from those of their neiglibours, and 

 therefore without intermediate coenenchyma. Calicos small, 

 pentagonal. Septa twelve or less, feebly developed, trabecular or 

 spinulose. A small columella, forming at its free end a knob or 

 a trabecular point or a style. Pali five or six, and not very distinct 

 from the septal ends, in a circle around the columella. Endotheca 

 exists sparingly, and may be dissepimental or tabulate, or may be 

 mere stereoplasm. 



Distribution. — Fossil. Eocene : Europe, Sind, Asia. Mio- 

 cene ; West Indies and Europe, Sind, Asia. — Becent. Red Sea, 

 Indian Ocean, Pacific, West Indies. 



This genus absorbs Stylarcea, Ed. & H,, 1851. 



The absence of any intercorallite reticular tissue or coenen- 

 chyma is invariable in the recent forms; but in the Eocene 

 Porites 'panicea, Lonsdale, there is a small quantity in some parts 

 of a colony, but not in all (Snpp. Brit. Foss. Corals, Pal. Soc. 

 1866, p. 63 ; P. M. Duncan). 



Genus Synarjea, Verrill, Bull. Mus. Comp. Zool. Cambridge, 

 Mass. 1864, No. 3, p. 42. 



Corallum irregularly branched or glomerate. Corallites with- 

 out distinct walls. The septa rudimentary. Six prominent and 

 paliform lobes surround the central cavity, which has a small 

 rudimentary tubercular columella. Outside of the pali are other 



