490 ALCYONIDIIDJE. 



Group a. Halcyonellea, Ehreuberg. 



Alcyonidul.e, Johnston, Brit. Zooph. ed. 1. 

 PoLYZoA CARNOSA, Gray. 



TiOk^iVM feshy or membranous. Zo(ecia developed by bud- 

 ding from other zocecia, and not from the internodes 

 of a stolon. 



Family I. — Alcyonidiidae. 



Alcyonidul^, Couch. 

 Halcyonelle^, Smitt. 



Zo(EciA more or less closely united, itnmersed in an expanded 

 and adherent gelatinous crust, or forming an erect cylin- 

 drical or compressed zoarium ; orifice closed by the mere 

 invagination of the tentacular sheath ; not protected by 

 external labia. 



Genus ALCYONIDIUM, Lamouroux. 



Der. From Alcyonitim, a genus of Actinozoa, to which the present was 

 supposed to bear some resemblance. 



Alcyonidium, Lamx. Exposit. Method. (1821) : Johnston: Couch: &c. 

 Alcyonium (part.), Linnaeus : Pallas : MilUer : Flemhig : &c. 

 Halodactylus, Farre (1837) : Van Beneden. 

 Cyc'loum (sp.), Hassall. 

 Sarcociiitum (sp.), Hassall. 



Generic Character. — Zocecia immersed or subim- 

 mersed ; the orifice simple, papilleeform. "Zoarium gelati- 

 nous or argillaceous, either crustaceous or erect. 



