20 ARKIV FÖR BOTANIK. BAND 14. N:0 0. 



Gromplioiiema x\g. 



Gomphonema exiguum Kütz. var. septentrionale (0str.). 

 — Gomphonema septentrioiiale östr. Mar. D. 0st-Grönl., p. 414, 

 Tab, 3, f. 9. 



Foss.: Kk. Knjäsha, rare. 



Distr. (mar.): West Arctic Sea. 



Cleve considers this variety to be identical with G. exi- 

 guum var. jjachydada Bréb. (V. H. Syn. Tab. 25, f. 31, 32), 

 though the latter is recorded to have 16 striae in 10 [J. (D. 

 Baff. Bay, p. 19). But as both 0strup's form and mine 

 have considerably coarser striae, viz. 12 and 10 resp. in 10 <^., 

 I still believe it correct to distinguish them from the Nor- 

 mandian var. pachyclada. 



Tracliyiieis Cl. 



Trachyneis aspera (Ehb.) var. vulgaris Cl. Syn. Nav. 

 D. I, p. 191. A. S. Atl. Tab. 48, f. 2—6. 



Foss.: Kk. Knjäsha, Koudajärvenpää, not rare. 



Distr. {mar.): Greenland, Faeroes (0strup), Arctic Ame- 

 rica, North Sea etc.; ubiquist. 



Trachyneis aspera (Ehb.) var. pulchella W. Sm. — Donk 



B. D. Tab. 10, f. 10. 



Foss.: Kk. Knjä,sha, Koudajärvenpää, frequent, 



Distr. {mar.): Greenland, Faeroes (0strup), North Sea 



etc.; ubiquist. 



Trachyneis aspera (Ehb.) var. intermedia Grun. Franz- 

 Jos.-L. D. Tab. 1, f. 20. 



Foss.: Kk. Knjäsha, not rare. 



Distr. {mar.): Greenland (0strup), East Arctic Sea, North 

 Sea. (Foss.) Hungary, Brunn, Japan. 



Naviculae Mimiseulae Cl. 



Navicula problematica n. sp. — PI. 4, f. 78. 

 Valve lanceolate, obtuse, hyaline, 24 [j. in length, 6 [J. in 

 breadth. Central nodule distinct. 

 Foss: Kk. Knjäsha {mar.), rare. 



