BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 21. AFD. III. N:0 2. 39 



and all the forms he there enumerates, together with some 

 few other arctic species, also occur in Lule Lappmark: 



CaJoneis ohfusa W. Sm. (Navicula Hebcs Ralfs.) 



Semen Ehb. 

 Cymbella heteroplenra Ehb. 



borealis Cl. 



incerta var. naviculacea GrRUN. 



lapponica Grun. 



norvegica GtRUN. 



cistula var. arciica Lägst. 

 Achnanthes margimdata Grun. 

 Eunotia lapponica Grun. 



triodon Ehb. 

 Diafomella Balfouriana Grev. 



and of a less decided arctic character: 



Pinnularia mesogongyla (Ehb.) Cl. 



diverg entissim a Grun. 



lata Bréb. 

 Neidium hisulcatiim Lägst. 

 Anomoeoneis serians Bréb. 



exilis Grun. 

 Cymbella hybridica Grég. 

 Denticula tenuis KtJTZ. 

 Melosira distans Kutz. 



There is also a great nuraber of forms whicli, thougli 

 now frequent in temperate regions, such as the southern part 

 of Sweden, Belginm etc, are not yet found in Lule Lappmark. 

 They are: 



Navicula gracilis (Kutz.) Grun. 



oblonga Kutz. 



viridula KiJTZ. 



cryptocepliala Kutz. 



gästrum (Ehb.) Donkin. 



cuspidata Kutz. 



v. ambigua Ehb. 

 Stauroneis aciita W. Sm. 

 Caloneis amphisbaena Bory. 

 Anomoeoneis spaerophora Kutz. 



