Mr. A. H. HassalPs Catalogue of Irish Zoophytes. 169 



Plumulabja. 



Plumularia falcata. This common species is sometimes found 

 branched, and attains a foot in height. The vesicles appear in spring. 



On stones and shells in deep water. Dublin bay ; abundant. 



P. cristata. On Fucus siliquosus ; rather common. Dublin and 

 Killiney bays. 



P. pinnata. — Dublin bay ; not common. 



Laomedea. 



Laomedea dichotoma. Polypidom usually from eight to ten inches 

 in height, but often more. 



Blackrock ; rather common. 



L. geniculata. Parasitic on sea- weeds, particularly on Laminaria 

 digitata and F. siliquosus. Dublin and Killiney bays ; common. 



L. gelatinosa. — Blackrock ; not common. The stem of this spe- 

 cies is ringed above and below the origin of each footstalk. 



Campantjlaria. 



Campanularia volubilis. This elegant microscopic species is fur- 

 nished with a delicate joint or hinge, situated at the base of each 

 little cup. This beautiful contrivance is designed, I imagine, to 

 enable this frail zoophyte the better to elude the rude contact of the 

 element by which it is surrounded, by permitting it to bend to a force 

 which it cannot resist. 



Dublin bay ; not common. 



C Syringa. Parasitic, as in also the preceding, on other corallines, 

 particularly on S. abietina. It is worthy of remark, that the more 

 delicate species of zoophytes affix themselves either to sea-weeds or 

 to others of a more robust nature. By so doing they receive the 

 shock communicated by the motion of the surrounding water, as it 

 were, second-hand — the force being first felt by, and partly expended 

 on, the objects to which they are attached before reaching them. 

 By this means also, a much wider range of motion is afforded them 

 for the capture of their prey, than they could possibly enjoy were 

 they rooted by their short pedicles to some fixed and unyielding sup- 

 port. 



C. verticillata. — Blackrock ; not very frequent. 



C. ? dumosa. This is now ascertained to be the Cornularia rugosa 

 of Cavolini, a figure of which is given in Dr. Johnston's ' British 

 Zoophytes.' Vignette 27. p. 187. 



Blackrock, on P. falcata, for which it manifests a decided pre- 

 ference ; not common. 



Order II. Z. ASTEROIDA. 



Alcyonidji. 



Alcyonium. 



Alcyonium digitatum. — On old shells, very common ; Dublin and 

 Killiney bays. 



