32 



KAARK MÜNSTKR STRMM. M.-N. Kl. 



Sidiinislniiii (iiKiliiiiiiii i'tir. (Willi lour arms.) 



A very icinarkablc variety ot Slaiird.^lnini (iikiIiiiiiiii occurred in Svart- 

 tjernet in Vestre Gausdal, in considerable quantities. Ail the specimens 



observed were four-rayed, but with the distinct markings of Stmirastnnu 

 (iiKiliiniiii. Some specimens, however, had developed the characteri.stic 



central spines of Statwaslniiii vcstihiiii. 



The specimens can by no means be referred to StaiirastriDii vcstilimi 

 var. siihaiialiniini, from which the variety differed in essential points. I hope 

 to give descriptions and drawings of the species in the „Algological Notes" 

 which I am going to publish. 



A good account of the whole group of these Sfaiirastra, especially the 

 pelagic forms, as well as a discussion of the relationship between species 

 in this group of the genus, should prove useful. 



Staiirastntiii Arac/iuc var. ciirvaftmi W. & G. S. West. 

 W. & G. S. West : Scott. Freshw. Plankton. 



This species occurred only in one lake in small quantities. The var. 

 citrvatiiDi is an exclusive plankton \ariety, being distributed also in the 

 British lakes. 



Staurasfrum aversutn Luxdell. 

 Lundell: Desm. Suec. 



I have found this Staitrasti-itin only in a single lake \-iz. Tysselands- 

 vandet in Western Norway. It is a very great rarity, and I never observed 

 it from the benthos. It seems to be a true limnetic form, being much more 

 frequent in the plankton than elsewhere. The distribution of the species 

 is essentially Occidental. 



Staitrastriiin Brasiliciisc var. LuudcUii \\\ & G. S. West. 

 W. & G. S. West : N. Americ. Desm. 



The Desmid was found in Sognsvandet near Christiania. It is principally 

 a tropical and subtropical Desmid, in temperate climates it is largel}- con- 

 fined to the plankton. In our lakes it is rare, the conditions here are, no 

 doubt, too severe for this Alga. 



Staiirastruni ciirvatimi W. West. 

 W. West: Freshw. Algæ W. Irel. 



Staurnatruiii citrvafiiin occurred in a single lake in small quantities. 

 The species is probably no exclusive limnetic form, but is much more fre- 

 quent in the plankton than elsewhere. Indeed, it is one of our rarest Desmids, 

 and I have never seen it in the benthos. 



Staitrastnmi ciispidatiiiit var. i/ia.viiii/mi W. West. 



W. West : Freshw. Algae. W. Yorkshire. 

 This variety of Sfaiirasfruiii cuspidafuiii is, as well the principal form 

 a frequent constituent of the fresliwater plankton, but is more limnetic 



