KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 



27. n:o 3. 17 



Var. leptocephala Bréb. (1880). — V. lanceolate, with slightly rostrate and obtuse ends. 

 L. 0,025; B. 0,006 mm. Strise 13 in 0,oi mm. — N. leptoceph. Bréb. in Ktitz Herb. accord. to Grun. 

 V. H. Syn. p. 82 Pl. VII f. 16. 



Belginm (V. H.). 



Var. Carl Ehb. (1838). — V. narrow lanceolate. L. 0,046; B. 0, 007 mm. Central area 

 distinct, transverse. Strise 17 in 0,oi mm. — N. Cari Ehb. Inf. p. 174. M. G. XII f. 20. V. H. 

 Syn. Vn f. 11. 



Fresh water: Habichtwalde, fossil (Ehb.), Anstralia, Uaintree River! 



Var. angusta Grun. (1860). — V. linear-lanceolate, obtuse. L. O, o 5 to 0,06ö; B. 0,oo5 to 

 0,006 mm. Central area distinctly transverse. Strise 12 to 13 in 0,oi mm. — N. angusta Grun. 

 Verb. 1860 p. 528 Pl. V f 19. iV. Cari v. ang. V. H. Syn. Pl. VII f. 17. 



Fresh ■n-ater: Austrian Alps (Grun.), Vosges (Lac de Gerardmer)! Ecuador! 



N. Cari conneets N. cincta witb N. radiosa and migbt as well be regarded as a variety of 

 the latter, distinguished principally by its somewhat transverse central area. 



10. N. radiosa Kutz (1844). — V. narrow, lanceolate, gradually tapering from the middle 

 to the subacute ends. L. 0, 045 to 0, 09; B. 0, 012 to 0, 019 mm. Axial area indistinct. Central 

 area very small, rhomboidal. Striae 11 to 12 in 0,oi mm. strongly radiate in the middle and con- 

 vergent at the ends, finely lineate. — Bac. p. 91 Pl. IV f. 23. Finn. radiosa and F. acuta W. Sm. 

 B. D. p. 56 Pl. XVIII f. 171, 173. N. radiosa Grun. Verh. 1860 p. 526. A. S. Atl. XLVII f. 50 

 to 52. V. H. Syn. p. 83 Pl VII f. 20. Finn. acuta Ströse Klicken f 2. 



Fresh water: Spitsbergen (Lagerst.). Sweden! Norway! Finland! England! France! Switzer- 

 land! Saxony! Japan! South Africa! Illinois! Michigan! Brazil! Argentina! Ecuador! 



Var. dubravicensis Grun. (1882). — V. broadly lanceolate. L. 0, 072 to 0,085; B. 0,oii mm. 

 Strise 13 in 0,oi mm., more distant in the middle, distinctly lineate; lineolse 25 in 0,oi mm. — 

 F. D. Öst. Ung. p. 144 Pl. XXX f. 49. N. Duhrav. Pant. III Pl. XIX f. 281 (1893). 



Fresh water: Hungary, fossil (Grun.). 



Var. subrostrata Cl. — Linear with subrostrate, obtuse ends. L. 0,o85; B. 0,oii mm. 

 Strise 10 in 0,oi mm. — Pinnul tennis Greg. M. J. II Pl. IV f. 9 (1854)? 



Fresh water: Crane Pond (N. Am.)! 



Var. tenella Bréb. (1849). — Lanceolate with acute ends. L. 0,o3 to 0,o65; B. 0, 005 to 

 0,006 mm. Strise 15 to 18 in 0, 01 mm. — N. tenella Bréb. in Kutz Sp. Alg. p. 74. N. radiosa 

 v. ten. V. H. Syn. p, 84 Pl. VII f. 21, 22. 



Fresh water: Sweden! Finland! Belginm (V. H.), Japan! Australia (Daintree Hiver)! Tas- 

 mania! Greenland! Argentina! 



Pantocsek describes as N. tenella var.? fossilis (II p. 54 Pl. V f. 91) a form with broad 

 axial area, which, if the figure be exact, cannot belong to JSf. radiosa. 



Var. minutissima Grun. (1882). — 0, 01 7 to 0,027; B. 0,oo35 to 0,oo4 mm. Strise 14 to 19 

 in 0,01 mm. — F. D. Öst. Ung. p. 144. 



Fresh water: Hungary, fossil (Grun.), Rostock, fossil! 



This var. seems rather to belong to N. cryptocephala v. veneta. 



11. N. gracilis Ehb. (1830). — V. almost linear, obtuse. L. 0,033 to O.os; B. 0,oo6d to 

 0,01 mm. Axial area indistinct; central area distinct, transverse. Strise 11 to 12 in 0, 01 mm., in 

 the middle slightly radiate, elsewhere almost parallel. — Ber. 1830 Inf. p. 176 Pl. XIII f. 2(?) 

 Grun. Verh. 1860 p. 526 Pl. IV f. 27. V. H. Syn. p. 83 Pl. VH f 7, 8. 



Fresh water: Sweden! Finland! Denmark! Normandy! Arctic America! Argentina, Sierra 

 Famatina ! 



Var. schizonemoides V. H. (1880). — Frustules enclosed in iinbranched, gelatinons tubes. 

 Central area somewhat smaller. — Colletonema neglectmn Thwaites in W. Sm. B. D. II p. 70 Pl. LVI 



K. Sv. Vet. Akad. Handl. Band 27. N:o 3. 3 



