HYDROIDA. 453 



brought thence by Mr. Hjiidman are remarkably fine, their ordmary 

 height being 9 inches ; some of them, too, branch profusely, so as to occupy 

 nearly as much space in breadth as in height : — one specimen had at- 

 tained the height of 12 inches. Nov., 1842, attached to Pecten maxiinus 

 in Belfast market ; the shells stated to have been dredged in the Bay. 

 W. T. 



T. Beunii, Johnst. 



Procured by dredging in Belfast Bay, where it in some situations seems 

 to take the place of T. halecuui. Before it was described as a distinct 

 species, its peculiarities, independently of the remarkable ovaries, were 

 noticed by Mr. Hyndman and myself; its general aspect or habit first 

 attracted our attention. Instead of the rigid " herring bone " appearance 

 of T. haU'cina, it is somewhat flexible and graceful. Although not men- 

 tioned in the description, this difi'erence is observable in the plates of the 

 British Zoophytes. 



Among Zoophytes collected in Dublin Bay, by Prof. Harvey, in 1834, 

 and kindly sent to me, were examples of this sjiecies. Adherent to 

 oysters dredged at Killough, Co. Down. W. T. 



T. muricata, Johnst. 



For the only Irish specimen, a mere fragment of this TIkxi which I 

 have seen, I am indebted to Dr. Hassall, who found it near the Giant's 

 Causeway. W. T. 1842. 



Genus Sertulabia. 

 S. jJolyzonias, Linn. 



Dublin Bay, 1834, Prof. Harvey. Youghal, Miss Ball. Magilligan, Co. 

 Londonderry, Mr. Hyndman. This is one of our most common Sertu- 

 Jaricp, on the coasts of Down and Antrim, and indeed those of Ireland 

 generally ; it is usually attached to Ahjce and Zoophytes, more especially 

 to Halixlrys siliquosa and Flustra foJiaeea. The largest and finest speci- 

 mens I have seen were from deep water, where, even on our northern 

 coasts, they in more than one locality attained the magnitude mentioned 

 by Templeton of o inches in height. See his description of S. 2>itt>i(tta. 

 The Sertalaria which commonly passes under the name of jmlyzonias in 

 Ireland is the form figured in Ellis, and which is considered by M. Ed- 

 wards distinct from the erect form represented on the same plate. He 

 names the flexuous form »S'. Ellisii. 



All the specimens in my collection from various localities, whether 

 growing in a flexuous or erect state, winding round the stem of Algse, or 

 expanding in an arborescent form, with a single main stem (if it may so 

 be called), have the cells Avith a toothed rim, and the vesicles toothed. 

 I have not seen any vesicles with such an orifice as is represented in the 

 erect form by Ellis, plate 2, fig. A; 



S. rugosa, Linn. 



On Flnstrn folineen collected at Magilligan, Co. Londonderry, by Mr. 

 Hyndman, 183S. On same species from Bootle coast, Liverj)ool, Mr. 

 Henry Johnston, 1840 ; and on same, dredged at Sana Island, off" the Mull 

 f Cantire, Mr. Hyndman, 1841. 



<S'. rosaeea, Linn. 

 Dublin Bay, 1834, Prof. Harvey. April, 183.5. 



