20 KAAKK MIJ'NSTKK STKØM M.-N. Kl. 



(jfiiiis ( i(Hii/ili(>sjili(rri<i Kt Kl/. 1836. 

 ('•(>iii/ylinspli(fri(i /((ciislris Chod. 



Cmodai : ICtudcs de Biologic lacustre. 

 This truc |)lankton-species was rare in two samples, 



Gojiipliosplin'ria /a( //s/ris vai'. couipniia Licmm. 



Lkmmkrmann : Planktonalg. i. Ergcbn. e. Reise n. ci. Pacific 1899. 



This Alga was very common in the two samples from the Vansje lake. 

 It has not yet been recoi^ded from many localities, but has doubtlessly 

 a world-wide distribution, being reported on from the Wakatipu lake 

 in New Zealand. ^ 



Order Hormogonece. 

 Family s dilator iacece. 

 Genus OsciZ/nfor/a Valxhf.r 1803. 

 Oscillator ia tenuis Ac. 



Agardh: Alg. Dec. II. 

 This Oscillatoi-ia-spitclt's occurred in great quantities in two lakes in 

 the western districts, being a true plankton-Alga at least in one of them. 

 Oscillatoria tenuis is one of the very commonest of the Oscillatoria-species, 

 but it has seldom been reported on from the plankton. 



C/ass Peridineæ. 



Order Peridiniales. 

 Family Krossodiniaceæ. 



Genus Peridiniuui Ehrbg. 

 Peridiniuni JVestii Lemm. 



Lemmermann in W. & G. S. West: A furth. Contrib. to the Freshw. 

 Plank. 



This rare species of Peridiniuni occurred in small quantities in jolster- 

 vandet. 



Genus Ceratiuni Schrank 1793. 

 Ceratimn curvirostre Huitf.-Kaas. 



Huitfeldt-Kaas : Die limn. Peridin. i. Norw. Binnenseen. 

 This most extraordinary species was rather common in a single lake 

 in Western Norway. Messrs. West ha\-e reported on it from the Scottish 

 lakes, but it is not known from an}' other part of the world. It seems to 

 be confined to the western shores of Europe, and it would be interesting 

 to see if it may be found in the eastern districts of U. S. A. or Canada. 

 PL I, Fig-. 9. 



Ceratiuni hirundincUa O. F. M. Resting-spores. 



Resting-spores of the species were rather common in some lakes, notably 

 in Selsvandet. They occurred together with the \egetative state. 

 PL I, Fig's 10 & 12. 



