FAMILIES AND GENERA OF THE MADBEPORABIA. 185 



This genus was shown by Milne-Edwards and Jules Haime to 

 absorb Gemmipora, Blainville, and Explanaria (pars), Lamarck. 



Grenus Aste^opoea, Blainville, Diet, des Sci. Nat. t. ix. p. 348 



(1830). 

 The colony is massive in shape, adherent or incrusting. The 

 coenenchyma is lax, and decidedly echinulate at the surface. The 

 septa are unequally developed on the small calices. There is no 

 columella. Tabulae are seen in some specimens. 



Distrihidion. — Fossil. Eocene of Europe and "West Indies. 

 Miocene : Sind, Asia. — Becent. Red Sea, Indian and Pacific 

 Oceans. 



Genus Dendeacis, 3Iilne-Eilwards Sf Jules Saime, Hist. Nat. 

 des Corall. vol. iii. p. 169 (1860). 

 The colony is arborescent, and the coenenchyma is very dense 

 and granulated at the surface. Calices submammiform. Septa 

 few in number, subequal. ISTo columella. 

 Dist7'ibution. — Fossil. Eocene of Europe. 



Grenus Actinacis, d^Orhigny, Note sur les Folyp.foss. p. 11 

 (1849). 



Colony subdendroid, with a greatly developed coenenchyma, 

 which is rather dense and granulated, and not very perforated. 

 Calices circular, small, distant. Septa few in number, subequal, 

 somewhat exsert. A columella, which is papillose. Pali exist 

 before all the septa. 



Bistrihutioji. — Fossil. Cretaceous of Europe. 



Grenus Pal^acis, J. Haime, 1860. (Amended by Seebach, Zeits. 

 der Deutsch. Greol. Gresellsch. Bd. xviii. p. 308, Berlin, 

 1866.) 



Syn. SpTienopoterium, Meek and "Worthen. 



Colony pedunculate, cuneiform. Calices immersed in a vermi- 

 culate perforate coenenchyma, marked with anastomosing stria- 

 tions. Calice-walls of the same structure as the coenenchyma, 

 thick, but porous. Calicular margins circular in outline. Calices 

 widely open. Septal system of fine, numerous, unequal stria- 

 tions (30). G-emmation intercalicular, and producing occasionally 

 by pressure polygonal calicular margins. 



Distribution. — Fossil. Carboniferous : America, 



