KONGL. SV. VET. AKADEMIENS HANDLINGAR. KAND 27. N:0 3. 15 



3. N. rhyncliocephala Kutz (1844). — V. lanceolate, witli protracted, iisually subcapitate 

 ends. L. 0,04 to 0,og; B. 0,oi to 0,oi3 mm. Axial area indistinct. Central area orbicular. Strise 

 10 to 12 in 0.01 mm., in the middle radiate and more distant, convergent at tlie ends, coarsely 

 lineate. — Bac. Pl. XXX f. 35. W. Sm. B. D. Pl. XVI f. 132. Donk. B. D. p. 38 Pl. VI f. 4. 

 Grun. a. D. p. 33 Pl. II f. 33. V. H. Syn. p 84 Pl. VII f. 31. N. cryptoc. v. rhynclwc. Strösse 

 Kliecken Pl. I f. 3. 



Fresli or sliglitly brackish water: Finmarken! Sea of Kära! Grulf of Bothnia! Sweden! 

 Belgium (V. H.), Saxon}'! Cape Deschneff! Arctic America! Dakota! Illinois! South Africa! Au- 

 stralian Alps! 



Var. amphiceros KiJTZ (1844). — V. broader lanceolate. Ends not distinctly capitate. Strise 

 8 to 10 in 0,01 mm. — N. amph. Kutz. Bac. p. 95 Pl. III f. 39. A. S. Atl. XLVII f. 25, 26. 

 V. H. Syn. p. 84 Pl. VII f. 30. 



Brackish water: Gnlf of Bothnia! England! Belgium (V. H.), Sandwich Islands! 



N. rhyncliocephala and rar. amphiceros pass into each other; the latter graduates into 

 N. avcnacea and N. viridida, the former is closely connected with N. cryptocep)hala. 



4. N. aveiiacea Bréb. (1878), — V. lanceolate, with acute ends. L. 0,o4 to 0,0.5; B. 0,oo8 

 to 0,0 1 mm. Axial area indistinct; central area orbicular, large. Strite 10 or 12 (middle) to 13 

 (ends) in 0, 01 mm., iinely lineate, radiate in the middle, slightly convergent in the ends. — Grun. 

 Caspian Sea Alg. IV f. 23. N. viridida v. av. V. H. Syn. p. 84 Pl. VII f. 27. Pinmd. silesiaca 

 Bleisch (according to Grun.). Schizonema Smithii (Ag.) V. H. Syn. p. 110 Pl. XV f. 33. 



Brackish water: Falaise (Bréb.), England! Belgium (V. H.), Black Sea! Caspian Sea (Grun.), 

 East Cape! Tasmania! 



N- avcnacea connects N. viridula with N. rhynchocephala. 



5. N. viridula Kutz (1844). — V. broadly lanceolate, with subrostrate, obtuse ends. L. 0,0 5 

 to 0,07; B. 0,01 to 0,01.5 mm. Axial area indistinct. Central area large, orbicular. Striaä 10 in 

 0,01 mm., coarsely lineate, radiate and more distant in the middle, slightly convergent in the 

 ends. — Bac. p. 91 Pl. XXX f. 47. Grun. A. D. p. 33 Pl. II f 35. V. H. Syn. p. 84 Pl. VII 

 f. 25. Schizonema Thtvaite.sii V. H. Syn. Pl. XV f. 38, 39. 



Fresh and slightly brackish water: Sweden! England! Belgium (V. H.), Finland! Salzburg! 

 Sandwich Islands! — Australian Alps! Murray River! — Arctic America! 



Var. .^lesricennis Grun. (I88O). — V. linear-lanceolate, with broad, rostrate ends. L. 0,o3 

 to 0,05; B. 0,009 to 0,011 mm. Strise 8 to 9 in 0,oi mm. — N. sles. Grun. in V. H. Syn. p. 84 

 Pl. VII f. 28, 29. N. virid. f. minor A. S. Atl. XLVII f. 48. V. H. Syn. p. 84 Pl. VII f 26. 

 Pinmd. silesiaca Fresenius Senckenb. Abh. IV, Pl. IV f. 27. 



Brackish water: Finland! Holstein! Belgium (V. H.), Greenland! 



Var. abhrevicda Grun. Ms. — V. linear, with rostrate and subcapitate ends. L. O.oie to 

 0,03; B. 0,0055 to 0,007 mm. Central area small. Striee 16 to 17 in 0, 01 mm. 



Brackish water: Gulf of Bothnia, Torneå! South Africa! Bengal! 



Var. rostellafa Kutz (1844). — V. lanceolate, with attenuated, subrostrate ends. L. 0, 04 to 

 0.065; B. 0,01 mm. Striée 10 to 11 in 0,oi ram. — N. rost. Kutz Bac. p. 95 Pl. III f. 65. A. S 

 Atl. XLVII f. 27 to 30. N. rhynchoc. v. rost. Grun. A. D. p. 33. V. H. Syn. p. 84 Pl. VII f. 23, 24. 



Brackish water: England! Belgium (V. H.), Marseilles (Atl.), East Cape! Japan! 



The variety rostellafa is a transitional form between N. viridida and JSf. amphirhynchus var. 

 amphiceros. 



6. N. vnlpina KtiTZ (1844). — V. lanceolate, gradually tapering from the middle to the 

 obtuse ends. L. 0,o9; B. 0, 014 to 0,oi6 mm. Axial area very narrow; central area large, orbicular. 

 Strife 10 to 11 in 0, 01 mm., radiate in the middle, convergent in the ends, coarsely lineate; lineolae 



