118 Dr. J. E. Gray on the Fleshy Alcyonoid Corals. 



The skin of the body and the fleshy substance between the 

 bodies of this group of polypes are also studded Avith various- 

 shaped calcareous spicules, the fusiform being the most com- 

 mon. The spicules were observed and studied by J. Ellis, 

 and by various physiologists since his time, especially by Prof. 

 Kolliker, in his ' Icones Histiologies ;' but they require to* 

 be studied with more care and in a more philosophic manner, 

 so as to divide the forms into different groups by observing 

 the modifications which the spicules of each species undergo 

 when being developed, and also in a larger number of kinds, 

 before they can be used for the distinction of the genera and 

 species. 



Lamarck, in his Monograph on Alcyonium, first published 

 in the ' Annales dn Muse'um,' and then in the l Hist. Nat. des 

 Anim. s. Verteb.' (ii. 412), described many species that I have 

 not been able to identify or place in this synopsis. Though 

 most of them are described from specimens then in the Museum 

 of the Jarclin des Plantes, they are not further described or 

 in any way referred to in Milne-Edwards and Haime's 

 ' Coralliaires,' founded on specimens in that collection ; so it 

 is to be feared that the types have been lost. Some of them, 

 like some of the Alcyonia figured by Esper and other zoolo- 

 gists, were, very likely, sponges. Considering the number of 

 species that Ehrenberg and Quoy and Gaimard collected, and 

 the very few localities from which the specimens described have 

 been received, there must be very many species of these ani- 

 mals to be discovered, if they were only sought for in other 

 localities. They are very easily preserved ; so there is very 

 little excuse for their not having been more collected and 

 studied. 



Section I. DEKMOCORALLIA. 



The coral crust-like, attached by the lower surface, or lobed 

 and branched, with polypes on the whole of the exposed sur- 

 face. 



A. The coral crust-like, attached by the lower surface. The body of 

 the polype short. 



Earn. 1. Antheliadss. 



Coral crust- or skin-like, spreading, and attached by the 

 lower surface. Polypes produced above the surface of the 

 coral, not retractile. Spicules fusiform or cylindrical, spinous 

 or tubercular. 



This family is somewhat like Xeniada?, and chiefly differs in 

 ] iroducing buds only at the base of the cells ; in this way the 

 coral is expanded outward, and forms an incrusting plate. 





