2 TABULATE CORALS. 



i 

 cavity, instead of occupying only the one or two loculi. It is 



also to be remembered that the septal apparatus, though more 

 or less rudimentary, has the same general mode of arrangement 

 as in the preceding sub-orders " (Aporosa and Perforata), " and 

 never presents the crucial character which we shall find in the 

 Zoantharia Rugosa" They also divide the " Tabulata " into 

 the following four families, comprising the under-mentioned 

 genera : 



Fain. I. MILLEPORID^E. Corallum principally composed of a very abundant 

 ccenenchyma, distinct from the walls of the corallites, and of a tubular or 

 cellular structure. Septa not numerous ; tabulae numerous and well formed. 

 Genera Millepora, Lam.; Heliopora, De Blainv. ; Heliolites, Dana; Fistuli- 

 pora, M'Coy ; Plasmopora, Edw. and H.; Propora, Edw. and H. ; Axopora, 

 Edw. and H. ; Lobopora, Edw. and H. 



Earn. II. FAVOSITID^E. Corallum essentially formed by lamellar walls, with 

 little or no coenenchyma. Visceral chambers divided by numerous and 

 well-developed complete tabulae. 



Tribe i. Favositince. Corallum massive. Walls perforated. Septa rudi- 

 mentary. No coenenchyma. Genera Favosites, Lam. ; Michelinia, 

 De Kon. ; Koninckia, Edw. and H. ; Alveolites, Lam. 

 Tribe 2. Chcetetince. Corallum massive. Walls not perforated. Neither 

 septa nor ccenenchyma. Genera Chcetetes, Fischer; Dania, Edw. 

 and H ; Stenopora, Lonsd. ; and Constellaria, Dana. 

 Tribe 3. Halysitince. Corallum composed of corallites constituting verti- 

 cal laminae or fasciculi, but more or less free laterally, and united by 

 means of connecting tubes or mural expansions. Walls well developed, 

 and not porous. Septa distinct, but small. Genera Halysites, 

 Fischer; Harmodites, Fischer (subsequently abandoned for Syringo- 

 pora, Goldf.), and Thecostegites, Edw. and H. 



Tribe 4. Pocilloporina. Corallum massive, gibbous, or subdendroid, 

 with thick imperforated walls, forming towards the surface an abun- 

 dant compact coenenchyma. Septa quite rudimentary. Genus 

 Poallopora, Lam. 



Fam. III. SERIATOPORID/E. Corallum arborescent or bushy, with an abun- 

 dant compact ccenenchyma. Visceral chambers filling up by the growth 

 of the columella and the walls, and showing but few traces of tabulae. 

 Genera Seriatopora, Lam. ; Dendropora, Michelin ; Rhabdopora, Edw. 

 andH. 



Fam. IV. THECID^E. Corallum massive, with an abundant, compact, spuri- 

 ous coenenchyma, produced by the septa becoming cemented together 

 laterally. Tabulae numerous. Genus Thecia, Edw. and H. 



Various additions, modifications, and improvements in the 

 above classification of the " Tabulata" were made by Milne- 



