642 ZOOPHYTES. 



HYALONEMA SIEBOLDI. 



H. simplex, subcylindricum, ad basin attenuatum, non affixum (?) sed in 

 spongiam insitum; super fide granulosum et verrucosum, verrucis 

 grandibus, truncatis. 



Simple, subcylindrical, attenuate at base, and not attached (?) but 

 planted in a sponge; surface granulous and verrucose, verrucae 

 large, truncate. 



Japan. Dr. Siebold. 



Hyakmema Sieboldi, Gray, Proceed. Zool. Soc., 1835, pp. 63-65. 



GENUS III. BRIAREUM. BLAINVILLE. 



Gorgonidce axe inarticulate calcareo-spiculigero, aut suberoso ; polypis 

 sparsis. 



Gorgonidse having a non-jointed axis, containing calcareous spicula, or 

 suberose ; polyps scattered. 



The soft axis of these zoophytes appears to afford sufficient ground 

 for a generic distinction. They are placed by Blainville and Ehren- 

 berg on this account with the Alcyonia, and they actually form a con- 

 necting link between them and the Gorgoniae. Like the latter, how- 

 ever, the polyps, instead of extending to the base of the zoophyte, as 

 in the Alcyonia, extend inward and terminate against a central or 

 axial line ; and to this are due their arborescent forms, and the exist- 

 ence of an axis. This fact appears to be of more fundamental impor- 

 tance than the mere nature of the axis. The species arboreum and 

 suberosum are, with hesitation, united with the other species which is 

 properly the type of the genus. It is possible that they might better 

 be arranged near the Spoggodiae, which also seem to differ from the 

 other Alcyonida3 in an arborescent mode of growth, and the non-.exten- 

 sion of the polyp-visceral cavities to the base of the zoophyte. 



