156 The hish Naturalist. August, 



Thompson records H. viridis as having been obtained at 

 Bandon, Co. Cork, by Prof. Allman. //". grisea has been met 

 with in the north, south, and east of Ireland, several specimens 

 having been obtained at the Zoological Gardens, Dublin, in 

 1846, by Mr. Hyndmau. H. fusca has also occurred in the 

 north and east of Ireland (2, p. 459). 



Prof. L,eidy regarded the American green and brown types 

 of Hydra as being identical with the European forms — 

 //. viridis and II. fusca (4, p. 311) ; but the late Prof. Agassiz 

 found them to be quite different, and named them II. gracilis 

 and II camea, the chief differences being that H. gracilis has 

 the power (not possessed by H. viridis), of extending the body 

 in a remarkable degree ; and //. carnea has very short tentacles, 

 while H. fusca has very long ones (5, p. 354). 



Prof. Leidy obtained both forms west of the Rocky 

 Mountains, and these he found to accord in character with 

 the European species. In specimens collected in a lake in 

 the Uinta Mountains, Wyoming, at 10,000 feet elevation, the 

 brown Hydra was at first brick red with a brighter red head, 

 but after keeping it for a week, it assumed the pale brown hue, 

 as ordinarily observed in the animal nearer home (4, p. 312). 



H. fusca has been found in France at high elevations in 

 the Alps, in L,ac de Giinont and L,ac de 1' Ascension, whilst in 

 L,ac de la Roche it has been found along with //. viridis 

 (6, pp. 43-6i). 



References. 



• 



1. SEEEENS, F. M. (ill Proc. Dublin Micros. Club), Irish Naturalist, 



vol. x., 1901, p. 95. 



2. Thompson, W., Natural History of Ireland, vol. iv., 1856, p. 459. 



3. AeEMAN, G. J., The Synopsis of the Genera and vSpecies of Zoophytes 



inhabiting the Freshwaters of Ireland, Ann. Mag. Nat. Hist, 

 vol. xiii., 1844, p. 328. 



4. IyEiDY, J., Remarks on Hydra, Proc. Acad* Nat. Sc, Philad., 1887, 



pp. 311-313* 



5. AGASSiz, I*, Proc. Bos. Soc. Nat. Hist., vol. iii., 1850, p. 354. 



6. Beanchard, R., et Richard, J., Sur la Faune des Lacs eleves des 



Hautes-Alpes, Mem. Soc. Zool. France, vol. x., 1897, pp. 43-61. 



Science and Art Museum, Dublin. 



