330 



DE. 8. J. HICKSON — EEVISION OF THE 



The family ClavulariidEe is practically the same as the Cornulariidse of other writers, 

 but there are very good reasons for changing the name and adopting the one that I 

 have proposed. 



The genus Cornularia is distinguished from the other genera by the absence of 

 spicules and the presence of a considerable horny secretion on the polype-vcalls and 

 stolon. If this genus contained a large number of species, and it were at all a common 

 thing for the species of the other genera to have horny walls and be devoid of spicules, 

 Cornularia might be taken as the type of the family. But it is not so. Clavularia is 

 the genus with the largest number of species, and the absence of spicules and the 

 presence of a horny substance strengthening the walls of the polypes are phenomena 

 not very frequently met with in the family. It is better, then, to take Clavularia as 

 the typical genus. 



At the time of the appearance of the famous ' Histoire Naturelle des Coralliaires,' 

 by MM. Milne-Edwards and Haime, seven genera were recognized, and they were 

 arranged as follows : — 



"" Simples, a polypieroide tubulaixe et a pol}'pe retractile 



('des stolons radiciformes. f tubuliformes. 



Comularies •< 



Agregees, 

 portees <( 

 l_^ sur 



'retractiles. 



Haimeia. 



ni costulees ni 

 spiculiferes : 

 Cornularia. 



Polypieroides <( 



^une expansion membrani- 

 forme. 



Polypes ■( MuraiRes <( costulees et 



I I spiculiferes : 



Clavularia. 



\^ non retractiles. (^ Rhizoxenia. 



verruciformes Sarcodictyon. 



r retractUes . . Sympodium. 



Polypes 



I non retractiles Anthelia. 



If subsequent naturalists had followed closely the characters here given by the 

 French naturahsts, we might have been preserved from the extraordinary state of 

 confusion into which the group has now fallen ; but new species have been included 

 in the old genera without reference to the characters here given, new genera have been 

 created without any reason, adequate or otherwise, given in the text, and the figures, 

 in some cases, have been hopelessly at variance with the descriptions. To give here 

 just one example of the many I have come across: — The genus Bhizoxenia was estab- 

 lished by Ehrenberg (5) to include a species that he found in the Red Sea, charac- 

 terized by the fact that the polypes are not retractile, and Milne-Edwards and Haime 

 rely upon this as the one and only character separating this genus from Clavularia and 

 Cornularia. " Genre TV. Rhizoxenia. Polypieroiides comme dans les genres prece- 

 dents, mais polypes non retractiles." 



