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free zooids ; on another they presented a very different 

 appearance, having tuberculated lobes on the upper part, 

 and remaining attached during the whole time that the 

 polypite continued to live, about ten days. Mr. Alder had 

 little doubt of their continuing permanently fixed. He 

 conjectures that the distinction is a sexual one ; but we 

 must wait for further observations before we can decide 

 upon its significance. We have, I believe, no analogous 

 fact on record. 



Family XII. Pennariidae. 



POLYPITES with two sets of tentacles one oral and capitate, 

 the other aboral and filiform. 



Genus VORTICLAVA, Alder. 



GENERIC CHARACTER. Polypites borne on simple stems, 

 developed at intervals on a creeping filiform stolon, the whole 

 ccenosarc clothed with a very delicate film-like polypary (?); 

 tentacles in two dissimilar verticils the oral short and capi- 

 tate, the aboral long and filiform. 



Reproduction unknown. 



THIS genus was founded by Alder after the examination of 

 a single specimen, which had probably not attained its full 

 development. He describes the polypite as solitary and 

 naked; and Wright assigns the same characters to his V. 

 proteus. In both cases, however, I believe, the individuals 

 observed were merely primary polypites, and would have 

 given origin in time to a creeping stolon on which other po- 

 lypites would have been developed. I have a specimen of 

 Vorticlava (obtained at Salcombe in South Devon) which 



K.2 



