CONTRIBUTIONS TO THE BRITISH FAUNA. 249 



I have kept it alive several days, I have never 

 observed it in an upright position. It in ge- 

 neral hangs downwards, as expressed in the 

 figure, sometimes, however, it is nearly horizon- 

 tal. 



It is chiefly found on the leaves of Fucus digi- 

 tatus, and F. esculentus, which grow in deep water. 

 It is common in Zetland. 



At first I was disposed to consider this species 

 as the Liicernaria quadricornis of Miiller, (Zool. 

 Dan. i. tab. 39. fig. 1) ; but a more careful com- 

 parison of the figure and description with the 

 Zetland specimens, has convinced me of the pro- 

 priety of viewing them as distinct species. In 

 Z. quadricornis, the branches of. the arms arq 

 represented as terminating in a fasciculus of about 

 forty tentacula ; whereas, in Z. J'ascicularis, the 

 tentacula are upwards of a hundred in number.- — 

 (Communicated 9th December I8O9.) 



7. Caryophyllia cyathus. (Lamark.) 



Madrepora cyathus, — Ellis, Zooph. p. 184. tab. 28. 

 fig. 1—4. 



Coral white, hard, striated on the outside, and 

 rough. Margin denticulated by the plates of the 

 gills. Star oval, containing forty or fifty gills, 

 with an equal number of intermediate smaller 

 ones ; the latter reaching to the margin, but not to 

 the centre as the larger ones do. In the centre of 

 the star, there is a prominent ridge in the direc-- 

 tion of its greatest diameter. This ridge is com- 



