CLASSIFICATORY POSITIOX OF SOME MABREPORARIA. 



131 



Cryptoccenia is thus modified by the same hand : — " Coenenchyma 

 abundant and of a loose nature, composed of a great many dissopimen- 

 tal tabulae, from which the gemmation takes place quite distinct from, 

 the walls of the corallites. Septa well developed, and their cycles 

 distinct. The calices not crowded, always round and on the same 

 level." This is a new definition altogether. Xow, although the 

 presence of tabulae is asserted in this genus, the forms are not placed 

 in the Tabulata by Mr. Tomes, as are the species of Cyatlwpliora. 

 To those palaeontologists who have not studied the Corals these 

 definitions may appear to be very distinctive ; but such is not 

 the case. The amount of coenenchyma in these forms is a matter 

 of growth ; the cyclical arrangement of the septa and their length 

 are clear in some forms ; but no one can doubt that the condition of 

 the septa in the miserable specimens of the form named CiJoarr/i^.^ii, 

 so miserable that Mr. Tomes confesses that he cannot make out 

 the real affinities, is due to weather and fossilization. The cyclical 

 arrangement of the worn-down septa, which look like mere ridges 

 on the inside of the wall, can be made out by the septal number and 

 by the costae. 



The gemmation is, in all the forms, extra- calicular, and that is an 

 important point, for it is perfectly well known that in Stylina the 

 gemmation is always extra- calicular, and is usually from the inter- 

 mural space, or, it may be, from the wall outside the calice. The 

 crowding or the reverse of the calices is also a matter of individual 

 growth, and is not generic. 



Notwithstanding the indifi'erent structural details of the form 

 Bourgueti, Mr. Tomes asserts its identity with the species described 

 by Michelin, and therefore relegates all the species which Milne- 

 Edwards described as belonging to CyatJiophora, Michelin, to the old 

 genus Cryptoccenia. Mr. Tomes altered the generic titles of the 

 species described by myself as CyatlioplwrcE^ but he was not quite 

 sure that he was right, and he writes as follows : — " But if, on the 

 other hand, it \_Cyathoijliora Bourgueti] should eventually prove to 

 differ from CyafJiojJ^iora generically, then the genus Cryptoccenia 

 must be dropped, and a new genus formed to receive the present 

 species ; for this Depapliyllmn would not be an inappropriate name."' 

 Cryptoccenia thus stands on a very slight foundation. 



The fact is, that neither of the genera enlarged upon by Mr. 

 Tomes belongs to the Tabulata ; that Milne-Edwards and Jules 

 Haime were correct in associating certain Cryptoccenia with Gyatlio- 

 pliora^ Mich. ; and that the distinctions attempted to be drawn be- 

 tween Cyatliopjhora, as elaborated by the authors just mentioned, and 

 the ill-defined genus Cryptoccenia, d'Orb., are insufficient, and are 

 founded upon the observation of bad specimens. 



In concluding this reference to the impropriety of altering the 

 generic names of the Cyatliophorce given by Milne-Edwards and 

 myself in the ' British Fossil Corals,' it is necessary to mention that 

 Cryptoccenia micropJiylla, Tomes, of which a figure is given (Quart. 

 Journ. Geol. Soc. vol. xxxix. pi. vii. fig. 2), has all the specific 

 characters of Cyathopliora iuherosa, nobis, except that this last is a 



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