323 



THE PHYTOPLANKTON OF THE ENGLISH 

 LAKE DISTRICT. 



Wm. west, F.L.S., 



AND 



G. S. WEST, M.A., D.Sc, F.L.S., 



{Continued from page 2^2). 

 Flagellata. 

 23. Mallomonas longiseta Lemm. in Arkiv for Botanik 

 utgifv. af K. Sv. Vet.-Akad. Bd. 2, No. 2, 1904, p. 118. 



This Flagellate was observed in Brothers' Water, Easedale 

 Tarn, and Windermere ; and in the first-mentioned lake it was 



Fig. 7. A., Dinobryon cylindyicum Imhof, from the plankton of Crum- 

 mock Water, showing three resting spores ; B., D. cylindricum var. 

 diver gens (Imhof) Lemm., from the plankton of Derwent Water ; C. and D., 

 D. crenulatum sp. n., from the plankton of Ennerdale Water. All x 500. 



the dominant constituent of the September plankton. Long, 

 cell, 29.5-37 /x; lat. cell, 17-21. 5 /x ; long, spin., 54-62 /.i. 

 It is known in the plankton of the Scottish lakes, but this is 

 the first English record. The spiny covering is particularly 

 conspicuous in this species, and the cell possesses a single 

 brown parietal chromatophore and one flagellum. 



1909 Sep. I 



