BIHANG TILL K. sv. VET.-AKAD. HANDL. BAND. 21. AFD. III. N:0 2. 11 



Var. tennis A. Cl. n. var. ~ A. S. XLV, 62. 

 Valve only lialf as broad as the typical form, 0,oö6 mm. 

 in breadtli, 0,04 to 0,045 mm. in lengtli. 



Ks. 15, S.-K. 22, 33, Nu. 5, 19, Ll. 21. — Somewhat rare. 



P. biceps GrRÉG. — Nav. bicapitata Lägst., Spitsb. pl. I, 5, — 



A. S. XLV, 70. 



Length of the valve 0,o6 mm. 



Kv. 1, Jm. 6, Ks. 15, 20, Km. 30, Gl. 43. — Not rare. 



Var. stauroneiformis Cl. Ms. — A. S. XLV, 72. 



Length of the valve 0,04 mm. Striae interrupted in the 

 middle of the valve. 



Ks. 15. — Rare. 



P. borealis Ehb. — V. H. VI, 3. 



Kv. 32, Nu. 2, 5, U, 17, 18, 25, 37, 41, Jm. 6, Km. 10, 30, 

 Tr. 38, V. 12, S.-K. 7, 33. — Freqnent. 



P. lata BRéB. — V. H. VI, 1. 



Kv. 1, 2Q, 28, 32, Nu. 3, 11, 17, 18, 37, 39. — Rather freqnent. 



P. nndnlata Grég. — Cl. Finl. pl. II, 8, p. 30. 

 Ks. 15. — Rare. 



Navicula Bory. 



Sectio: N. lineolatse. (Radiosse). 



N. vulpina KtJTZ. — V. H. VII, 18. 

 Jm. 6, Ke. 49. — Rare. 



N. radiosa KtJTZ. — V. H. VII, 24. 



Kv. 1, 9, 26, 32, S.-K. 7, 33, Jm. 6, Ks. 15, 20, Tr. 38, 

 Ll. 21, Km. 30, Ke. 49. — Freqnent. 



N. Cari Ehb. — V. H. VII, 11, 17. 

 Nu. 25. — Very rare. 



N. cincta KtJTZ. — V. H. VII, 13. 



Of this species a broad (0,oi mm.) form occnrs sparingly 

 in Kv. 9. 



N. anglica Ralfs. — V. H. VIII, 29, 30. 



Kv. 32, Km. 30, S.-K. 7. — Somewhat rare. 



N. dicephala (Ehb.?) W. Sm. — V. H. VIII, 33, 31. 

 S.-K. 7, Tr. 38. — Rare. 



