132 Rev. T. Hincks on Norwegian 



that must be formed for its reception Hydrodendron ; it may 

 be characterized as follows : — 



Suborder THECAPHORA. 



Family Haleciidae. 



Hydrodendron^ n. gen. 



Generic character. — Zoophyte plant-like, much branched, 

 rooted by a creeping stolon ; hydrothecaj biserial, tubular, 

 jointed to a short lateral process from the stem ; polypites 

 very large, partially retractile ; tentaculoid appendages 

 minute, filiform, naked, terminating above in a subglobose 

 capitulum filled with thread-cells, distributed over the stem 

 and branches, one below each calycle ; gonothecse unknown. 



Hydrodendron gorgonoide^ G. O. Sars (sp. unic). 

 The polypites of this interesting form are remarkably large, 

 furnished witli about twenty-four tentacles, and of a bright 

 yellow colour. The compound stem is thick and rugged and 

 irregularly branched, and when covered with its conspicuous 

 coloured polypites, the species bears, as Sars has remarked, a 

 striking resemblance to a Oorgonia. It is peculiarly tree-like 

 in appearance, and fully entitled to the generic name which I 

 have given it. It has many characteristic features ; but of 

 course its principal distinction is to be found in the curious 

 appendages to which I have referred. 



Lafoea fruticosay M. Sars. 

 Amongst the Lafoeidge included in Sars's catalogue of Nor- 

 wegian species is the L. fruticosa, M. Sars, which was de- 

 scribed many years since by his father in his ' Zoologisk Reise 

 i Lofoten og Finmarken.' This form I have identified with 

 the L. gracilUma^ Alder*; and in doing so I had the concur- 

 rence of Mr. Alder himself, who believed that his species was 

 identical with the Norwegian, and that his name must yield 

 to the earlier designation conferred by Sars. Mr. G. O. Sars, 

 however, thinks that I have decided wrongly ; he figures what 

 he supposes to be his father's species, and holds that it is 

 certainly distinct from L. gracilUma. In this, I have no 

 doubt, he is right ; I have as little doubt that his figure does 

 not represent L. fruticosa, but another and very different 

 species. It is, in fact, referable to the form which I have else- 

 where described as Lafoea grandis^. 



* ' History of British Hydroid Zoophytes/ i. p. 202. 

 t Vide a paper in the present Number of the ' Annals ' on Icelandic 

 Hydroida {infriX, p. 148). 



