ÖFVERSIGT AF K. VETENSK.-AKAD, FÖRHANDLINGAR 1899, N:0 8. 833 



The four collections from Virijaure, though gathered in dis- 

 tant parts of the lake (from tlie S.E, to the N.W. corner), all 

 show much the same character. Mostly the same species occur 

 and the differences as to theiv relative frequency are slight. I 

 therefore give a coUective list of the observed species. 



Plankton very scarce, Zooplankton predominating, desmids 

 and diatoms not rare, Dinobiyon less frequent. 



Entomostracans: 



Daphnia (^Cephaloxus) cristata G. O. Sars, No. 10. 



» hyalina Leydig, No. 12. 

 Bosmina ohtusirostris G. O. Sars, No. 10. 



» » v. arctica LiLLJEBORG, No. 11. 



Diaptomus graciloides LiLLJEBORG, Nos 10, 12. 

 » laticeps G. O. Sars, Nos 9, 11, 12. 



Cyclops sGutifer G. O. Sars, Nos 9, 10, 11, 12. 



Rotatorians: 



Hydronella pygmoia CaLman, No. 12, r. 



Notholca longispina Kellicott, Nos 9, 10, 11, 12, + . 



Anurea aculeata Ehb., Nos 9, 12, r. 



» cochlearis GossE, Nos 10, 11, 12, + . 



Flagellates: 



Dinobryon sertularia Ehb., Nos 9, 10, 11, 12, — . 

 Desmids: 



Arthrodesmus Fucus (Bréb.) Hass., Nos 9, 10, 11, 12, +. 



Staurastrum avicula Bréb., Nos 9, 10, 11, 12, — . 

 » dejectum Bréb., Nos 9, 10, 11, 12, — . 



» paradoxum Mey., Nos 9, 10, 11, 12, — . 



Diatoms: 



Asterionella formosa v. subtilis Grun., Nos 9, 10, 11, 12, + . 



Tabellaria fenestrata v. asterionelloides Grün., V. H., PI. 

 LH f. 9, Nos 9, 10, 11, 12, +. 



T. fenestrata v. geniculata A. Cleve, Nos 9, 10, 11, 12, +. 



Melosira tenuissima Grun., Nos 9, 10, 11, 12, — . 



Surirella oregonica Ehb., Nos 10, 12, r. 



