— 236 - 



observations made by Miss A. Cleve 1 ) concerning the phytoplankton 

 of lakes in Lule Lappmark it will be seen, that the plant-organisms 

 are much the same in Lomnæssjon as in the forest lakes in Lapp- 

 mark, viz. Dinobryon , Tabellaria f enestrata and flocculosa and 

 Asterionella formosa. The Myxophyceœ and Peridiniaceœ are entirely 

 absent, and the Chlorophyceœ rare; the occurrence in Lomnæssjon 

 of some species of the latter, viz. Sphœrocystis, Botryococcus (and 

 also the brown alga Stichogloea) are without doubt due to the small 

 mountain-stream, Harren a, which runs from the lake Harsjön to 

 Lomnæssjon and carries with it some plankton specimens from the 

 former. 



In August 1899 Dinobryon was absent, and the plankton con- 

 sisted of a few diatoms and Chlorophyceœ only; it seems rather 

 odd that the plant-organisms were so scarce, while the animals 

 were very numerous, and I must admit, that I am not prepared 

 to give an exhaustive explanation of this fact. 





Lomnæssjon 



Harsjön 





1900 



1899 



1900 



1899 



Chlorophyceæ. 



25 /t 



13 /s 



17 / 7 



8 /s 











Sphærocystis Schroeteri Chodat 



rr 



rr 



c 



C 



Trochiscia sp 





• 





r 



Botryococcus Braunii Kütz 





rr 



c 



c 



Crucigenia rectangularis (A. Br.) Chodat 







rr 



_i_ 



Raphidium fasciculatum Kütz 









r 



Nephrocytium Asardhianum Næg 







rr 





Pediastrum Boryanum (Turp.) Menesh 









rr 



Closterium Kuetzingii Bréb 





■ 



. rr 



rr 



Cosmarium phaseolus Bréb 









• rr 



— tetrophthalmum (Kütz.) Menegh. . . 











Gosmocladium saxonicum De Bary 









rr 



Docidium Ehrenbergii Bréb 







• rr 





Euastrum verrucosum Ehbg. . 







• rr 





Gonatozygon asperum (Bréb.) Cleve 







• rr 







rr 



rr 



rr 



rr 



Micrasterias crenata Bréb 









rr 



') Cleve, Astrid: Notes on the plankton of some lakes in Lule Lappmark, 

 Sweden. — Öfv. af k. Vetensk. Akad. Forhandl. 1899, No. 8, pp. 825-835. 

 Stockholm. 



