I92I. No. 4- THE PHYTOPLANKTON OF SOME NORWEGIAN LAKES. 37 



Oocvsfis parva W. & G. S. West. 



W. & G. S. West : Notes on Freshw. Algae. 



The species occurred together with the preceding, but in small quan- 

 tities. It is more abundant in the plankton than elsewhere, but stricdy 

 speaking no real limnetic Alga. The Alga should never be confused with 

 Oocvsfis piisilla Hansg. 



Order Oedogoniales. 

 Family Oedogoniacece. 

 Genus Ocdogoiiiiiiii Link 1820. 



0('(/ogo/ii/i//i pa/iu/os/u/i (Hass.) Wittr. 

 Wittrock : Prodr. Monogr. Oedogon. 



Lat. cell, veget. 16,5 — 16,5 [j.. 

 Long. oosp. 54 [X, 54,5 iM, 55 [X, ^^ [J., 55 [i., 57,5 [J., 59 [X. 54—59 [X. 

 lat. oosp. 38 [J., 35 [X, 37,5 [X, 41 [X, 41,5 |x, 42 [X, 40 |x, 35 — 42 [X. 

 lat. oog. 45 [X, 38,5 [X, 43,5 [X, 50 IX, 47,5 [X, 47,5 [X, 47,5 [X, 38,5 — 50 [x. 



The Alga occurred in the plankton of Nedre Sjodalsvand. — I have 

 measured seven specimens of the form. The species is quite benthonic in 

 its habitat, and the few specimens in the plankton are only casual con- 

 stitituents. 



Order Heterokontœ. 

 Family Botryococcacece. 



Genus Acti>iobotrys W. & G. S. West 1905. {-— Askenas3'ella). 



Actinohotrys coiifcrtus W. & G. S. West. 



W. & G. S. West : Fourth. Contrib. Freshw. Plankton Scott. Lochs. 

 This interesting Alga was not unfrequent in two lakes. It is character- 

 istic plankton Alga, probably quite ubiquitous in its occurrence. 



Protozoa. 



LitliocoUa Apstciiiii Huitf.-Kaas. 



This species is the only one I have noticed from the Norwegian fresh- 

 water plankton. — It is very possible that quite a number of other species 

 may be found, and I also observed several Protozoans in the collections, 

 but they were too much affected by the preserving chemicals, to be recog- 

 nized and referred to their proper places in the system. 



