420 Notes on the Crustacean Fauna of the English Lakes. 



already referred to., I found also D. mucronata and D. reticulata, 

 the latter in very great abundance. But in pools of this kind 

 occurring at a greater elevation, the Daphnise seem to give 

 place to another member of the same family — Acantholeberis 

 cuTvirostris — which will presently be noticed. 



Sida crystallina (Mull.) occurs plentifully amongst reeds 

 and rushes round the margin of lakes, but does not, apparently, 

 reach any great elevation. 



Acantboleberis curvirostris (Miil].). — This species is not 

 uncommon throughout the British islands in pools of peaty 

 water, ranging from near the sea-level to considerable eleva- 

 tions. It does not so often occur in clear lakes and tarns. 

 Sprinkling Tarn, and Crag Lake, Northumberland, are the 

 only such localities in which I have any record of its occur- 

 rence. 



Ilyocryptus sordidus (Lievin) . — A rare and curious species, 

 of which I found two specimens in my gathering from the 

 peaty pools in Ennerdale. It had previously been found,, 

 though very sparingly, in two situations in Northumberland 

 and Durham. 



Drepanothrix hamata, G. 0. Sars, is of not unfrequent 

 occurrence in the upland districts of the north of England and 

 south of Scotland, frequenting lakes and clear water. In the 

 Lake district, I have found it in Bydal Water, Blea Tarn 

 (Langdale), Little Langdale Tarn, and Easdale Tarn. 



Polyphemus pediculus, Mull., though common in the 

 moorland lochs of Northumberland and southern Scotland, is 

 not so in the Cumberland district, the only lake in which I 

 have found it being Derwentwater. 



Bosmina longirostris (Mull.) and B. longispina, Leydig, 

 occur, one or both of them, in almost all pieces of water in 

 the Lake district. The males of these animals differ remark- 

 ably from the females in having the anterior antennas con- 

 nected with the body by a sort of ball-and-socket joint, 

 and in the tapered form of the abdomen. This sex is, 

 however, rarely met with; the only place in which I have 

 found it being a small rushy tarn on some hills, called the 

 Humbles, on the north-western border of Northumberland. 

 This pool contained abundance of the Bosmina, but scarcely 

 any other species ; and I found this to be the case also in a 

 somewhat similar situation on the northern slope of Mickle 

 Fell, in Yorkshire ; but in this latter case my gathering con- 

 tained no males. 



Lyncku.s HAEPJ! (Baird), a very common species in almost 

 all clear pieces of water throughout the kingdom, and on the 

 continent of Europe, seems little affected by elevation, l>"ing 

 met with in almost all the pools, lakes, and tarns of the Lake 

 district. 



