42 ARKIV FÖR BOTANIK. BAND IJt. NIO 9. 



Foss.: Kk. Knjäsha, frequent. 



Distr. (mar.): West and East Arctic Sea, North Sea, 

 Mediterranean Sea, America, Austr., Antarctis. 



I am not sure whether the Finlandian form is identical 

 with Cleve's var. typica, that is stated to have only 5 — 6 

 costae in 10 [j-. 



Achiiaiitlies Borg. 



Microneis Cl. 



Achnanthes exilis Kütz. — V. H. Syn. Tab. 27, f. 16—19. 



Valve 9 [j- in length, 3 u. in breadth. Striae 18 in 10 [i. 



Foss.: Ab. Hindersmossen. 



Distr. {fresh iv.): Belgium, Germany. 



Finlandian specimens are only about half as long and 

 broad as the typical ones, according to Cleve (Syn. Nav. 

 D. II, p. 189). 



Achnanthes septentrionalis 0str. var. subcapitata 0str. 

 D. N.-E. Greenl, p. 115, Tab. 13, f. 22. 



Foss.: Kk. Knjäsha, not rare. 



Distr. (mar.): N.-E. Greenland. 



The rather frequent occurrence of this species, hitherto 

 known only from Greenland, in the Knjäsha-material is of 

 interest. Both valves agree perfectly with 0strup's descrip- 

 tion. The frustule is distinctly genuflexed. 



Achnanthes delicatula Kütz. — V. H. Syn. Tab. 27, 

 f. 3, 4. 



Foss.: Kk. Knjäsha, rare. 



Distr. {brack. io.)\ West Arctic Sea, North Sea, Balearic 

 Islands, San Francisco, Asia, Africa. 



Achnanthes polaris 0str. Mar. D. 0st-Gr0nl., p. 408, 

 Tab. 7, f. 86. Cleve, Baff. Bay, Tab. 1, f. 5. 



Foss.: Kk. Knjäsha, several specimens. 



Distr. {mar.): West and East Arctic Sea. 



In the middle of the epitheca, one stria is frequently 

 shortened. 



I 



