KONGL. SV. VET. AKADEMIENS HANDLINGAK. BAND 27. N:0 3. 



11 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18.' 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 

 30. 

 31. 

 32. 

 33. 

 34. 



(Valve with undulate margins 

 — — non — — 

 f Fresh water habitat . . 

 \ Marine .... 



N. Sancti Thomce Cl. 



7. • 

 . N. ludloviana A. S. 

 .... 8. 



( Striae not reaching to the margin N. suhalata Geun. 



\ — reaching 9. 



( Ends obtuse 10. 



\ — acute . . . 14. 



I Ends broad, rounded 11. 



\ — not very broad . . . . IS. 



f Axial area gradually dilated to the middle . . . . 



I — — abruptly — — a central area . . . 



f Size small. L. about 0,0 5 mm. . .... 



\ — large. L. about 0,i mm. . . ... 



J Axial area lanceolate . . 



I — — abruptly dilated into an orbicular central area 



J Striae radiate throughout 



\ — transverse in the ends . .... . . . 



f Striae crossed by a blank band ... .... 



\ — not — — — ... 



( Striae radiate 



\ — • parallel 



{Terminal striae parallel or convergent 

 — — radiate . ... 



J Terminal striae crossed by a lunate band . . . 



\ — — not — — — . • . . 



{Terminal striae genuflexed . ... ... 



— — not — ... 



I Striae crossed by lateral areas or by narrow blank bands . 

 I — not — — — — — — 



f Median striae of unequal length . 



t Valve lanceolate, rostrate-capitate . 

 i — — not — — 



[ Valve acute 



[ — obtuse 



Median striae alternately longer and shorter N. Salinarwm v. intermedia. 



[ — — shorter than the others N. notabilis Pant. 



Striae line, 20 in 0,oi mm . . N. bottnica Geun. 



N. jamalinensis Cl. 

 . N. opima Geun. 



13. 



. N. distans W. Sm. 



N. Nicceensis Pee. 



. . . N. salva A. S. 



N. Flatessa Cl. 



... .15. 



. N. Bruchii Geun. 



N. Amicorwm Geun. 



17. 



82. 



18. 



54. 



N. annulata Geun. 

 . . 19. 

 N. oblcmga K.tiTz. 



30. 

 21. 

 22. 

 36. 

 28. 

 23. 

 24. 

 25. 



\ — coarse, 8 to 9 mm. 



j Striae coarsely lineate 



\ — finely — 



I Striae 6 in 0,0 1 mm 



1-9 



I Terminal striae strongly convergent 



( — — parallel 



( Length 0,025 to 0,037 mm 



I — 0,115 mm 



I Striae crossed by a lateral area 



( — — — two or more blank bands 



{Valve obtuse . . 

 — acute .... 



I Valve linear, with rounded ends 



( — lanceolate 



(Lateral area unilateral 

 — areas bilateral 



j Longitudinal bands two on each side . . . 

 \ — — several — ... 



26. 



27. 



N. digito-radiata Gees. 



. N. peregrina Ehb. 



N. Beinhardtii Geun. 



. . N. Wilczekii Gkun. 



. N. Salinarimi Geun. 



N. Rho Cl. 



.... .31. 



. . 34. 



32. 



. . 33. 



N. obtwsa Cl. 



. . N. Saueri Geun. 



JV. Anthracis Be. a. Cl. 



N. Bruchii Geun. 



... 35. 



N. Tuscula Ehb. 



Conf. N- hasaltm proxima Be. and N. aquitanice Be. (additional) 



