96 



COELENTERATA-~ANTHOZOA 



SUB-BRANCH II 



Sub-Family C. PORITINAE. Milne-Edwards and Haime. 

 >Vy//V mil nrii numerous, well developed. Corallites united by their porous walls. 



Litharaea, E. and H. (Fig. 170). Massive coralla. Calices sub-polygonal; 

 septa generally in three cycles ; columella spongy. Eocene and Miocene. 



Pihodaraea, E. and H. Massive coralla. Spurious walls of corallites thick ; 

 pali prominent. Miocene and Eecent. 



Porites, Lam. (Fig. 171). Massive or branching coralla. Calices shallow, 

 polygonal ; septa irregularly reticulated ; columella papillous, surrounded by 



Fio. 171. 



Porites incrustans, Reuss. Miocene; 

 Moravia. a, Transverse section ; 

 b, Longitudinal section. Both figures 

 highly magnified. 



FIG. 172. 



, Alveopora spongiosu, Dana. Recent; Fiji Islands. 

 Longitudinal section of corallite showing perforate Avails 

 and tabulae; b, Alveopora ntdis, Reuss. Nununulitic lime- 

 stone ; Oberburg, Styria, 1/1 ; c, Calices, greatly enlar^-d. 

 (Fig. a, after Dana ; b, after Reuss). 



single cycle of pali. Cretaceous to Recent. The genus Porites is one of the 

 most important of existing reef-builders. 



Protaraea and Stylaraea, E. and H. Usually encrusting coralla with poly- 

 gonal calices. Visceral chambers partitioned off by horizontal tabulae. Silurian 

 and Devonian. 



Sub-Family D. ALVEOPORINAE. Verrill. 



Septa composed of detached trabeculae, spines, or reticulated lamellae. T/teca 

 perforate. Visceral cluimber ivith perforate tabulae. 



Alveopora, Quoy and Gaim. (Fig. 172). Massive coralla. Calices small, 

 polygonal. Septa represented by detached spinous processes. Tabulae sparsely 

 developed, remotely situated. Tertiary and Recent. 



Koninckia, E. and H. Cretaceous. 



Family 5. Madreporidae. Dana. 



Composite, branching, or lobate coralla with small tubiform corallites embedded in 

 a canaliculated and reticulated coenenchyma. Septa (6-12) sometimes imperfectly 

 developed. Two long septa projected from opposite sides and meeting in the centre. 



The genus Madrepora, Lin. (Fig. 173), is an important agent in the con- 

 struction of existing coral reefs, and builds colonies sometimes of considerable 

 size. It occurs sparsely in the fossil state in the Tertiary. 



Range and Distribution of the Hexacoralla. 



The group Aporosa of the Hexacoralla appears to have originated from the 

 Tetracoralla, and to form the direct continuation of their line. They begin as 



