BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 21. AFD. III. N:0 2. 23 



In Kv. 26, Ks. 15 tlie typical form occiirs, together with 

 the f. subcapitata Gr. in V. H. XXIII, 5. 

 f. elongata A. Cl. 

 Valve elongated, 0,06 to 0,o7 mm. in lengtli. 

 Kv. 26. — Rare. 



Var. capitata Ehb. — V. H. XXIII, 7. 

 Kv. 1. — Hare. 



G. geminatiim Lyngb. — Cl. 1. c. p. 186. 



Kv. 1, 9. 26, 32, 34, Km. 10, 30, V. 12, Nu. 17, 41, Ll. 21, 

 Tr. 38, Ke. 49. — Freqnent. 



G. ventricosum GrÉG. — V. H. XXV, 13. 



Ll. 21, Kv. 26, 32, 34, Km. 30, Tr. 38, Nu. 41. — Rather 

 freqnent. 



O. oliraceum Ehb. — V. H. XXV, 22—25. 



Kv. 34, Ke. 49. — Rare. 



Var. pusilla A. Cl. n. var. — Pl. I, 14. 



Valve 0,017 mm. in length, 0,oo4 mm. in breadth; striae 

 19 in 0,0 1 mm. 



Km. 30. — Rare. 



Cocconeis (Ehb.) Grun. 



C. Placentula Ehb. — V. H. XXX, 26. 27. 



Kv. 9, Ke. 49. — Rare. 



Achnanthes Bory. 



Å. borealis A. Cl. n. sp. — Pl. I, 24, 25. 



Valve elliptical, with subacute ends. O, o 2 mm. in lengtli, 

 0,01 mm. in breadth, the upper one with almost parallel 

 striae, 15 in 0,oi mm., leaving a blank semicircular space 

 near one of the margins. Lower (?) valve with a small 

 rounded central area, and delicate, strongly radiate striae, 

 21 in 0,01 mm. 



Ke. 49. — Rare. 



Both valves have not been seen together, but are found 

 in the same sample. 



