284 Mr. A. H. Plassall's Catalogue of Irish Zoophytes, 



furnished with minute cups, similar to those of the Cuttle-fish, by 

 means of which the polypi are enabled to. hold their prey ; and not, 

 as stated by Mr. Lister, covered with ** short projections, like blunt 

 hairs." The reproductive gemmules are supported on a short foot- 

 stalk, and are fewer in number and several times larger than those 

 of the preceding species. 



Dublin Bay, on various Fuci; not common. 



Tubularia larynx. Both varieties of this species are trawled up 

 in great abundance off Howth and Lambay. They are also found 

 attached to the under surface of stones, on the east side of Kings- 

 town Harbour. 



Thoa muricata. — Giant's Causeway. 



Sertularia Margareta. Polypidom branched, branches alternate ; 

 rachis straight ; cells nearly opposite, ovato-tubular, contracted on 

 the outer side ; vesicles 4-sided, armed with 8 long teeth. 



This species, in the absence of its remarkable vesicles, requires a 

 very careful examination to distinguish it from S. abietina. There 

 are, however, well-marked differences between them. The stem in 

 this species is straight, whereas in S. abietina it is flexuose ; the cells 

 are more nearly opposite, and are contracted on the outer side ; aper- 

 tures plain. The branches are alternate ; there are three cells on 

 the rachis in the interval between each branch. Vesicles 4-sided, 

 very large, increasing in size at the distal end, and armed near the 

 summit with 8 stout spines, two placed at each angle. 



To this new and interesting species I have assigned the Christian 

 name of a lady, distinguished not only for an ardent love of the 

 works of nature, but as a zealous collector in various branches of 

 natural history on these shores. See Plate VI. fig. 3, 4. 



A Sertularia is figured and described in Ellis's and Solander's 

 ' Zoophytes ' under the name of S. pinaster, which bears a consi- 

 derable resemblance to the above. I do not, however, believe them 

 to be of the same species, as the vesicles in this are furnished with 

 but four spines. 



Dredged up off Howth sparingly ; also found near the Giant's 

 Causeway. 



S. pumlla. The number of tentacula in this species is not very 

 constant, but usually about 16 : they are not disposed in any de- 

 terminate order, as they always are in the Ascidian type of Zoophytes, 

 but are variously arranged. 



Sertularia filicula. This species was incorrectly enumerated as 

 among those found in Dublin Bay in my Catalogue. It is not met 

 with upon that coast ; I have, however, obtained a few specimens in 

 the neighbourhood of the Giant's Causeway. 



Thuiaria articulata. The stem in the specimens found in Dublin 

 Bay is not naked on the lower half, as it is generally described, but 

 is clothed with pinnae to near its base, giving the polypidom a very 

 beautiful appearance. See Plate VII. fig. 1, 2. The specimen figured 

 in this plate is the finest I ever saw, and I could not resist the temp- 

 tation of giving a drawing of it. 



Not unfrequently obtained by trawling ojQf Howth, 



