THE ENTOMOSTRAOA OF LAKE BASSENTHWA1TE. 127 



Brief Statement of recorded Distribution in Britain of the Species taken 

 in Lake UassentJnvaite. 



ENTOMOSTEACA. 



Cladocera. 

 Bosmina longirostris, Baird. 

 Bosmina longirostris, Baird, British Entomostraea, p. 105, tab. xv. Fig. iii. 

 This species appears to be fairly common and widely distributed in 

 Britain. In Bassenthwaite it was very common in all the tow-nettings 

 in April, but rare in June. 



Sida crystallina, Straus. 



Sida crystallina, Baird, Brit. Entom. p. 107. 



Baird remarks that this species is of rare occurrence, but Scott records 

 it as being common in Raitli Lake in Scotland. It was the most 

 common species taken in April 1898. In June very few specimens 

 were taken, but these were of a large size, with well-developed ova and 

 embryos. 



Chydorus sphoeiicus, Baird. 

 Chydorus sphairicus, Baird, Brit. Entom. p. 126, tab. xvi. fig. S. 

 Common in ponds and ditches in Britain almost all the year round. 



Leptodora hyalina, Lilljeborg. 



Leptodora hyalina, Bronn, Klass. und Ordn. des Thier., Arthrop. Ci'ust. , Erste 

 Halfte, Tafeln, Taf. xxi. fig. 1. 



This species was first taken in England by Bolton 1 from the Olton 

 reservoir, near Birmingham. Later it was taken by Beck in Lake 

 Grasmere. Scott has taken it in the Scottish lakes (Loch Leven, Loch 

 Morar), and remarks that while it is considered to be a rare species, it is 

 not very rare in Loch Leven. 



In April only the larvae and very young forms were taken, chiefly at 

 the surface in Bassentfnvaite. In June this species was exceedingly 

 abundant, with eggs, embryos, and young, but no young larvae were 

 taken. It was, moreover, confined to the middle of the lake, where the 

 water is deep (see Map, p. 131). Very few mature specimens were 



1 Ann. & Mag. Nat. Hist. (5) vol. ix. p. 53. E. Ray Lankester, "On new 

 British Cladocera discovered by Mr. Conrad Beck in Grasmere Lake, 

 Westmoreland." 



