12 The Irish Natnralht. [Jamian-, 



KNTOMOSTRACA FROM I^OUGH RKK. 



BY W. 1'. DK V. KANE, M.A., F.E.S. 



[Collected on the Ivx:ursioii of the Dublin Naturalists' l''ieldClub, 1899. i 



Thk following resiiits were obtained from about an hour's 

 dredging in one portion of I^. Ree, and chiefly in deep water. 

 Only the most interesting captures are given. Several 

 specimens of Bythotrcphes hngimaniis, Lilljeborg, and Lepto- 

 dora hyalhia, I,illjeborg, occtirred ; these two remarkable 

 species frequent large lakes. Dr. Creighton has met w^itli 

 the former in L. Melvin, and the latter near Galway. When 

 the Athlone party broke up I proceeded to Mayo, and in 

 L. Mask met with both, but at L- Carra only Lepfodora 

 hyalina. Both also occur at L- Gill, Sligo, and L. Neagh- 

 In L. Erne the latter is found and a species of Bythofrcphcs, 

 probably B. borcalis, Sars., not hitherto taken in the British 

 Islands. Daphnia /aciistris, var. ga/cata. Sars., occurs 

 plentifully in moderately deep water at L. Ree. The 

 prevalent form i^ a most remarkable one and well worth 

 figuring. The helmet-shaped head assumes the most 

 grotesque forms, the beak being extremely prominent, a 

 ver}' convex projection in front of the eye, and the vertex 

 spine long and sometimes curved forward into a hook-shape. 

 When alive, the animals are remarkable for a vers' dark 

 pigmentation about the head and the abdomen, which gives 

 them a ver}- speckled appearance in the water, 'llic specimens 

 figured by Prof. Brady in his monograph on British Daphnia 

 published last year, from L. Oich and L. Attray, Scotland, are 

 suggestive of those which I took at I,. Ree, btit are not in any 

 way so grotesque. It is interesting also that I found the same 

 species in L. /uask in extraordinar\- ntimbers, and of exactl}- 

 similar character to those of L. Ree. I have taken D. galeata, 

 Scourfield, also in L. Gill and in certain minor lakes in the 

 County of Monaghan where tlie> occur in scanty numl^ers 

 accompanied by D. longispina and other common species? 

 but presenting in every instance onl}^ the ordinar}- typical 

 characters. The immature specimtrus taken at L. Ree and 

 L. Mask are extremeh' variable, but not more so than is 

 usual elsewhere, so far as I have examined. It is worth}' of 

 noting that this species, widely distributed in the lakes of 

 Ireland and Great Britain, appears on the Continent to be 



