102 PBor. p. MAETiN Duncan's eevision of the 



II. Alliance GONIASTR^OIDA. 



Massive fissiparous Astrseidae. Corallites united by their walls, without 

 coenenchyma, not forming serial calices. Septa dentated. 



Genus GoNrASTR^EA, Ed, & H, 

 Genus LAMELLASTRiEA, Duncau. 

 Genus Aphrastr^a, Ed. & H. 

 Genus Septastr^a, d'Orb. 



Grenus GtOniaste^a, Milne-Edwards Sf Jules Haime, Kist. Nat. 

 des Cor all. vol. ii. p. 444 (1857). 



Colony massive, convex or lobed, dense. Corallites prismatic, 

 and intimately united by their walls, which are simple, compact, 

 and thick. Calices polygonal, rather deep. Columella spongy. 

 Septa rather exsert, denticulate. Pali before all the septa, except 

 those of the last cycle, denticulate. Endotheca abundant. Com- 

 mon plateau covered by a thin and complete epitheca. Increase 

 by fissiparity and also by gemmation. 



Distribution. — Fossil. Cretaceous : Europe. Tertiary. — Recent. 

 Eed Sea, Indian Ocean, North- Australian seas, Pacific. 



Grenus Lameliaste^a, Duncan, Quarterly Journal of the Geolo- 

 gical Society ("Fossil Corals of the West-India Islands"), mo\. 

 xxiii. p. 19, pi. i. figs. 2 a, 2 6 (1867). 



Colony massive. Corallites united by their walls, and poly- 

 gonal in transverse outline. Calices polygonal. Columella essen- 

 tial and lamellar, stout. Septa unequal, dentated. Pali absent. 

 Endotheca scanty. Eeproduction by fissiparity through the 

 columella, a portion of it remaining as a large septum ; also by 

 marginal gemmation. 



Distribution. — Fossil. Miocene : West Indies. 



Grenus Apheastejsa, Milne-Edwards ^ Jules FLaime, Hist. Nat. 

 des Gorall. vol. ii. p'. 451 (1857). 



Colony convex and very light and cellular. Calices with simple 

 margins, polygonal. Walls very thick, but entirely vesicular. 

 Columella spongy. Septa exsert, dentate, with pali or paliform 

 lobes before all the cycles of septa except the last. Endotheca 

 vesicular and very developed. Increase by fissiparity. Common 

 plateau with a complete epitheca. 



Distribution.— Becent. Indian Ocean. 



