FAMILIES A.^T> GEIfERA OE THE MADBEPORARIA. 



103 



Q-enus Septastr^a, d'OrUgny, Note sur les Polyp, foss. p. 9 



(1849). 



Colony massive, subplane, convex or sub dendroid. Corallites 

 united by their walls. Calices polygonal, and their margins 

 soldered to those of their neighbours, forming simple ridges, or 

 shov^ing a delicate furrow of separation. Septa large. Columella 

 rudimentary or absent. Pali absent. Eissiparity of calices. 



Distribution. — Fossil. Lias : England, Europe. Eocene : 

 Europe. Miocene : America, Europe. 



CHAPTEE lY. 



Subfamily Astr^id^e agglomerate gemmantes. Alliances. Genera. 

 7. Subfamily Astrceidce agglomeratcB gemmantes. 



Syn. Stylinacece agglomeratce, Ed. & H. ; Astrceacece, Ed. & H. ; 

 MerulinacecB, Ed. & H. ; UcTiinoporidcs (pars), Ed. & H. : combined. 



Massive and foliaceous colonies. Corallites increasing by 

 gemmation from the wall, from within the calice, and from inter- 

 corallite tissue. Corallites joined by costse, exotheca, or peri- 

 theca, or fused by their walls. Septa entire or dentated. Endo- 

 theca vesicular, rarely tabulate. 



The Agglomerate Stylinse of Milne-Edwards and Jules Haime 

 {op. cit. vol. ii. -p. 232) were separated from their Astrseaceae, or 

 massive budding Astrseidse, because these last had dentate septa. 



In joining these groups into a subfamily no violence is done. 

 As a subfamily the genera collect very naturally into two groups 

 of Alliances. In one the corallites are separate, by their walls 

 being united by costse, exotheca, or peritheca ; and in the other 

 the walls are fused entirely, sometimes not joined at the calicular 

 surface. 



Alliance I. Orbicelloida. 

 „ II. Placoccenioida. 

 „ III. Stylinoida. 

 „ IV. Phylloccenioida. 

 „ V. Cyathophorida. 

 „ VI. Pentaccenioida. 

 „ VII. Elasmoccenioida. 



„ VIII. ECHINOPOROIDA. 



Group-Genus Galaxea, Oken. 



„ Leptastr^a, Ed. & H. 



