128 EDITH M. PRATT, B.SC. 



taken at the surface, or at the depth of 2 to 4 feet ; bat from 6 to 10 

 feet (10 feet = greatest depth at which tow-nettings were taken) it was 

 taken in great quantities. 



Bgthotrephes longimanus, Leydig. 



Bgthotrephes longimanus, Leydig, Naturgescliichte der Daphniden, p. 244, 

 figs. 73—75, Taf. x. 



British Habitat. — Scotland (Scott) : Loch Ness, Loch Morar (frequent 

 at surface), Loch Leven (frequent). Perthshire Lochs (Sept.) : Loch 

 Oich (common), Loch Tay (frequent at surface). 



This species has not been recorded before from the English lakes. 

 In Bassenthwaite it was very rare in April but very abundant in June, 

 with eggs, embryos, larvae, and young. 



Beck describes the species " cederstromii " from Grasmere and other 

 English lakes, and remarks that it appears to be more abundant in the 

 autumn than in the spring. 



Daphnia pulex, Latreille. 



Daphnia pulex, Baird, Brit. Entom. p. 89, tab. xvi., fig. 5. 



This species, while being widely distributed in ponds and ditches in 

 Britain, occurs but rarely in large sheets of water ; it was very rare in 

 Bassenthwaite in April, and no specimens were taken in June. 



Daphnia longispina. 



Daphnia longispina, Baird, Brit. Entom. p. 91, tab. vii., figs. 3, 4. 



This species was taken by Beck in English lakes and by Scott in 

 some of the Scottish lochs. It was rare in April, and no specimens 

 were taken in June. 



Polyphemus pediculus, Straus. 



Polyphemus pediculus, Baird, Brit. Entom., p. Ill, tab. xvii., fig. 1 ; Leydig, 

 Naturg. der Daphniden, p. 232, Taf. viii., fig. 63, Taf. ix., fig 71. 



Baird took specimens of this species in a ditch near Richmond-on- 

 Thames ; he remarks that this species seems to be very limited in its 

 range of habitat, as he only found it in one spot not more than 20 

 yards in extent. Scott, however, has taken it in many of the Scottish 

 lakes, and describes it as being a fairly common species, especially in 

 large sheets of water ; in Loch Morar, in Perthshire, it was taken by him 

 in abundance near the surface all over the portion of the loch examined. 



Beck took this species in the English lakes. It was very rare in 



