Mr. A. H. Hassall's Catalogue of Irish Zoophytes. 285 



Plumularia pinnata. Is generally found growing on a long fila- 

 mentous sea-weed, up the stem of which it creeps often for more 

 than a foot in extent, and round which the root-fibres form a com- 

 plete sheath. The specimens thrown up by the sea are usually de- 

 nuded of the short branches which proceed from the pinnae. The 

 vesicles are produced in great abundance, pyriform, blunt and plain 

 above : each vesicle contains 3 or 4 dark- coloured ova. Dr. John- 

 ston, in a letter I lately received from him, remarks, " I long ago 

 discovered the error of giving toothed vesicles to PI. pinnata : they 

 are only toothed from laceration, after the ova have esca])ed. It is 

 curious that the ova should be produced in such numbers from the 

 root- fibres; but such is a common occurrence with this pretty species." 



Tolerably abundant in various parts of Dublin Bay. 



Ft. setacea. The upper part of the vesicles of this species is pro- 

 longed into a short tube, affording an additional distinctive charac- 

 ter between it and PL pinnata, which it so closely resembles. 



Trawled up off Howth, very rare. 



PI. Catharina. Frequently trawled up off Howth and Lambay, 

 in deep water, and but rarely cast upon the shore. 



PL cristata. I have examined a specimen of this species, ob- 

 tained by my friend G. J. AUman, Esq., near Cork, having plumes 

 nearly three inches in length, and in which the ovarian vesicles are 

 produced only from the main stalks or midribs, giving to the whole 

 polypidora a very beautiful and unique appearance. 



PL myriophyUinn. Not common : obtained only by trawling off 

 Howth and Lambay, 



PL frutescens, I have met with but one specimen of this species, 

 consisting of a single plume elegantly tapering to a point above. 

 See Plate VIII. fig.~l. 



Alcyonidium rubrum, Miiller. Dr. Johnston considers this to be 

 but a mere variety of Alcyonidium digitatum, or that species in its 

 " primary crustaceous condition." That it is not Alcyonidium digi- 

 tatum in its primary crustaceous condition, I am convinced, from 

 the circumstance of having frequently met with it of a very large 

 size, as large as the ordinary species ever occurred to me, nor do I 

 consider it to be a variety ; for although no difference exists in the 

 number of the tentacuJa or in the form of the spiculse, it yet, in my 

 opinion, must lie regarded as a distinct species, as I have always 

 met with it of the same uniform deep red colour ; neither have I 

 been able to detect any gradations of colour between it and the 

 common kind, as might be expected were it but a variety. I have 

 occasionally, too, obtained both growing upon the same shell, each 

 possessing its own peculiar colour ; and this is a strong fact in fa- 

 vour of their distinctness, as the great difference in colour could 

 not be accounted for by a reference to any external causes, both 

 specimens being subjected to the same influences. 



Actinia mesembryanthemum.. Everywhere common off the coast 

 of Dublin. 



A. Bellis. " Body elongated ; the lower part narrow, smooth, the 



