nu 



Of these lakes, strictly speaking, only Sorvaagsvatn is largo 

 and of great depth; thc rost are generally small, more or less flat- 

 bottomed, and with shallow waler, and, consequently, typical plank- 

 ton occurs only in Sorvaagsvatn, while the rost of Ihe lakes, judg- 

 ing from the samples, contain a flora corresponding lo the flora 

 of small ponds and pools. 



We have had three samples for examination from Sorvaags- 

 vatn (see tahle I), onc from August 1897, and two from July 1899. 

 The plankton contained in them consisled mainly of animals, but 

 the two latter contained also a fairly large quantity of piants, 

 among which Dinobryon, Asterionella formosa and Desmids were 

 most conspicuous. Thus the character of the phyloplankton is 

 such as is usnal for the phyloplankton of the hilly regions 1 . 



Table I. 



CHLOROPHYCEAE. 



Sphaerocystis Schroeteri Chodal 



Gloeocystis vesiculosa Nag 



Scenedesmus quadricauda (Turp.) Bréb 



Pediastrum Boryanum (Turp.) Menegh 



Botryococcus Braunii Ktitz 



Cosmarium margen- Hi fe rum (Turp.) Menegh. 



Cosmarium Pbaseolus Bréb. f. 



Euaslrum elegans (Bréb.) Ktitz 



verrucosum Ehrenb 



Staurastrum jaculiferum West 



lunatum Ralfs 



crenulatum Nagl 



Magdalenae nov. spec 



Xanthidium quadricornutum Roy cl Biss. /'. 



MYXOPHYCEAE. 



Oscillatoria tenuis A;/ 



Chroococcus limneticus Lemm 



Microcystis incerta Lemm 



Sorvaagsvatn 



2C /8 



1S97 



5 / 7 

 1899 



+ 



B /7 



1899 



+ 



rr 

 rr 



1 See, cg. Borge, ().: Schwedisches Phy to plankton, Botaniska Notiser 1900. 



