FAMILIES ATfD QENERA OF THE AIADREPORARIA. 



179 



Grenus Placopsammta, Beuss, Sitzungsh. der Kais. AJcad. der 

 Wiss. Wien, Bd. xxxv. p. 486, pi. 2. fig. 16 (1859); Duncan, 

 " Deep -Sea and Littoral Corals,'' Proc. Zool. Soc. 1876, p. 441. 



Colony with a broad base, and short stunted projections, end- 

 ing in elliptical calices. Columella long and lamellary, compact. 

 Septa in four cycles, and with some of the orders uniting, as is 

 usual in the Eupsammida3. Costse visible to the base, often wavy 

 and inosculating. 



Distribution. — Fossil. Miocene, Oligocene : Europe. — Recent, 

 dalapagos ? 



Genus Astropsammia, Verrill, Notes on Badiata, p. 509 

 (1868-70). 



Colony massive. Corallites united to their summits by an 

 abundant, very porous coenenchyma. Walls scarcely distinct 

 from the coenenchyma, very porous. Septa in four cycles, with 

 some orders of the fifth ; those of the fourth unite to the tertiaries. 

 Columella usually well developed, composed of loose, convoluted, 

 and twisted lamellae and trabeculse. Interseptal spaces cut off 

 below by thin transverse dissepiments, which often coincide in all 

 the chambers. Calices shallow. Gremmation chiefly marginal and 

 interstitial. Fissiparity may occur. 



Distribution. — Recent. Mergui, Burmah ; Grulf of California. 



Some forms considered to be Coenopsammice, and which have 

 coenenchyma, belong to the next genus. 



Genus Pachtpsammia, Verrill, Proc. Esseoc Institute, vol. v. 

 (1866-67). 



Colony massive and incrusting. Corallites united near their 

 summits by a massive coenenchyma. Four complete cycles of 

 septa. Columella rudimentary or trabecular, not salient. Sur- 

 face of the coenenchyma with waving ribs. Gemmation lateral, 

 irregular. 



Distribution. — Recent. Chinese seas. 



This genus approaches Stereopsammia^ but has a solid coenen- 

 chyma. It differs from Dendrophyllia in not having' a distinct 

 columella. 



Genus Stereopsammia, Mihie-Edioards ^ Jules Haime^ Brit. 



Foss. Corals, Introd. Pal. Soc. p. 43 (1850). 

 Colony incrusting, glomerulate. Corallites short, united at 

 the base, free near the calice. Calices circular, rather deep, 



12* 



