100 CCELENTERATA. 



Metriophyllum, in the Permian Rocks by the genus Polycceha, 

 and in Tertiary deposits by the genus Conosmilia. 



APPENDIX GIVING A TABULAR VIEW OF THE DIVISIONS OF THE 



ZOANTHARIA SCLERODERMATA AND RUGOSA (AFTER 



MILNE-EDWARDS AND JULES HAIME). 



A. The Zoantharia Sclerodermata are defined by the possession of a 

 sclerodermic corallum, the parts of which are arranged in multiples of five 

 or six. Septa generally well developed, but not combined, as a rule, with 

 tabulae. 



The following chief divisions of the Zoantharia Sclerodermata are, with 

 few alterations, those adopted by the above-mentioned authorities : 



I. TABULATA. Septa rudimentary or absent ; tabulae well developed, 



dividing the visceral chamber into a series of stories. 



1. Thccidtz. Corallum massive ; a dense spurious coenenchyma formed 



by the lateral union of the septa ; tabulae numerous. 



2. FavositidtE. Septa and corallites distinct ; little or no true coenen- 



chyma. 



3. SeriatoporidcE. Corallum arborescent ; sclerenchyma abundant and 



compact ; tabulae few. 



4. Milkporida:. Corallum massive or foliaceous ; septa not numerous; 



sclerenchyma tabular or cellular. 



II. PERFORATA. Septa well developed ; no tabulae ; dissepiments rudi- 



mentary ; sclerenchyma porous. 



5. Eupsammida:. Corallum simple or composite ; septa well developed 



and lamellar ; columella spongiose. 



6. Poritida. Corallum composed of spongy, reticulated sclerenchyma. 



Septa never lamellar, but consisting wholly of a more or less definite 

 series of trabeculae ; no tabulae. 



7. Madreporida. Corallum usually composite ; coenenchyma abundant 



and spongy ; thecae porous, not distinct from the coenenchyma ; 

 septa distinct, but slightly perforate. 



III. APOROSA. Septa well developed, completely lamellar, and primi- 



tively consisting of six elements ; no tabulae ; sclerenchyma imper- 

 forate. 



8. Fungidte. Corallum simple or compound ; thecae ill developed, and 



somewhat porous ; no dissepiments or tabulae ; synapticulae numer- 

 ous. 



9. Astrteida. Corallum simple or compound ; no proper coenenchyma ; 



numerous dissepiments; no synapticulae. Corallites well denned, 

 and separated from one another by perfect walls. 



10. OfulinidtT. Corallum composite ; coenenchyma abundant and com- 

 pact ; dissepiments few in number. Walls of the corallites without 

 perforations, not distinct from the coenenchyma. 



11. Turbinolida. Corallum usually simple; no coenenchyma; septa 

 well developed ; no dissepiments, nor synapticuke. 



IV. TUBULOSA. Septa indicated by mere striae ; thecae pyriform ; coral- 



lites sometimes connected by a creeping basal coenenchyma. 



12. Autoporida. This being the only family in the Ttibulosa, its charac- 

 ters are necessarily the same as those of the division itself. 



B. ORDER RUGOSA. Characterised by the possession of a sclerodermic 

 corallum, usually with septa and tabulae combined, the former being in 

 multiples of four. The corallites are always distinct, and are never united 



