HYDROIUA. 459 



C. ? dumosa, Flem. 



On Tubtdariu imlivisa at Youghal, 1836, Miss Ball. 



On Serialaria lemUgera and various corallines in Belfast Bay, W. T. 



Dublin Bay, Dr. Ball, Sept., 1839. Bootle coast, Liverpool, from Mr. 

 Henry Johnston. Adherent to a stone from Strangford. Dredged in 

 about 40 fathoms water at Sana Island, by Mr. Hyndman, parasitic on 

 Tlmiaria articulata. Youghal, Miss Ball. Parasitic on various zoophytes ; 

 among others I have seen the delicate Serialaria lendif/era covered with its 

 tubes. Invests the upper portion of shells of the Dentaliuni entalis, di'edged 

 with the animals living iu Strangford Lough, July, 1838, W. T. 



C verticillata, Lamx. 

 Found commonly thrown ashore at Portmarnock, in 1835, and subse- 

 quently more rare, but of occasional occurrence in deep water in Belfast 

 Bay, W. T. Magilligan, Mr. Hyndman. Courtmasherry Harbour, Prof. 

 AUman, W. T. 



C. Integra, Macgill. 

 North of Ireland. 



Genus Hydra. 



H. viridis, Linn. 



East and South of Ireland. 



Obtained at Bandon (Co. Cork), by Prof. Allraan. 



H. vulgaris, Pall. 



North, East, and South of Ireland. August 20, 1846, I saw in a 

 glass globe — such as gold fish are kept in — half filled with water, in 

 Mr. Hyndman's house, about twenty living Ilgdrce, which were ob- 

 tained by him in May last, from the pond in the Zoological Gardens, 

 Dublin, a locality previously known by Mr. Callwell as frequented by 

 the species. Not one of these specimens showed any attenuation below, 

 and hence are not H. attenuata or //. oligactis. The tentacula are not 

 " shorter than the body," hence they are not H. viridis. They were 

 longer than the body and six in number in all the specimens, as I saw 

 them displayed. The colour of the body is a very pale reddish-brown. 

 When the body is fully extended, nearly 6 lines long, or 5 lines certain. 

 The tentacula are of about the same length, but when not so (and this 

 was the case in all but one specimen) they were considerably longer (5 

 lines). 



Hydra. See Johnston's Zoop., p. 131, 2nd edit. Effect of, on Limneus 

 pereger — Sept. 1846. Mr. Hyndman observing a Linmcus moving towards 

 a Hydra fixed on the side of a glass globe half filled with water, remarked 

 that the moment the tentacula of the Limtieiis touched the arms of the 

 Hydra, the Mollusc suddenly drew back and changed its course. The 

 Hydra did not draw in its arms. On a subsequent occasion, Mr. Hynd- 

 man observed a PUmorhis niurginatas (under half size) moving towards a 

 Hydra, and on coming in contact with its body, the Mollusc was not affect- 

 ed, but endeavoured to move onwards, at risk of (lis]jlacing the Hydra ; 

 this species, however, kept its ground, and the Phniorhis moved off' in the 

 direction of its arms, which were no sooner touched than it also, like the 

 Lijnneus, suddenlv drew back, and moved in another direction. The re- 



