.")0 1 FLUSTRELLID^E. 



Doubtful Species. 



ALCYONIDIUM RADIATUM, Alder, MS. 



IN his Report on Shetland Polyzoa, Norman mentions a 

 species of Alcyonidium which he had found between tide- 

 marks in the Out Skerries, and to which Mr. Alder had 

 given the above (manuscript) name. No description of 

 it has been published. 



Family II. Flustrellidae. 

 HALCYONELLE.E (part.), Smitt. 



ZOCECIA immersed in a gelatinous crust ; orifice bilabiate. 

 LARVAE furnished with a bivalve shell. 



Genus FLUSTRELLA, Gray. 



Der. Dim. of Flustra, the sea-mat. 



FLUSTRELLA, Gray, B.M. Cat. Radiata : Redfern : Alder : &c. 

 FLUSTRA (part.), Fleming : Blainville : Johnston : Couch : llincks : &c. 

 ALCYONIDIUM (part.), Smitt. 

 (Not FLUSTRELLA of D'Orbigny.) 



GENERIC CHARACTER. ZOCECIA immersed, the orifice 

 bilabiate, with a movable lip, which acts as an operculum. 

 ZOARIUM a gelatinous crust. 



THIS genus is distinguished from Alcyonidium, with 

 which it agrees in most points, by an important difference 

 in the structure of the orifice. It is furnished with a 



