KONGI.. SV. VI'lT. AKADEMIENS IlAKDLTNf! AK. HANI) 27. N:(> 3. 15 



3. N. rliyiicliocephala Ivutz (1844). — V. lanceolate, with protracted, usually subcapitate 

 ends. L. (),04 to (),o6; B. 0,01 to 0,01:3 min. Axial area indistinct. Central area orl)icular. Stria; 

 10 to 12 in 0.01 mm., in the middle i-adiatc and more distant, convergent at the ends, coars(dy 

 lineate. — Bac. PI. XXX f. 35. W. Sm. B. 1). PI. XVI f. 132. Donk. B. T). p. 3« Bl. VI f. 4. 

 (Irun. a. D. p. 33 PI. IT f. 33. V. H. Syn. p 84 PI. VII f. 31. N. cryptoc. v. rhynchoc. Strosse 

 Kliecken PL I f. 3. 



Fresh or slightly brackish water: Finmarkoi! Sea of Kara! Gulf of Bothnia! Sweden! 

 Belgium (V. H.), Saxony! Cape Deschneif! Arctic America! Dakota! lllinius! South Africa! Au- 

 stralian Alps ! 



Var. amphiceros KtJTZ (1844). — V. broader lanceolate. Ends not distinctly capitate. Striae 

 8 to 10 in 0,01 mm. — N. awph. Kvtz. Bac. p. Do PI. Ill f. 39. A. S. Atl. XLVIT f. 25, 2(\. 

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



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



N. rhynchoe(phal(i and var. amphiceros pass into each other; the latter graduates into 

 N. (irnuicca and A'. rirUhila, the former is closely connected with N. cryptocepihala. 



4. N. avenacea Br6b. (1878), — V. lanceolate, with acute ends. L. 0,o4 to 0,05; B. 0,oo8 

 to 0,01 nun. Axial area indistinct; central area orbicular, large. Stria; 10 or 12 (middle) to 13 

 (ends) in r),ui mm., finely lineate, radiate in the middle, slightly convergent in the ends. — Grun. 

 Caspian Sea Alg. IV f. 23. N. viridula v. av. V. H. Syn. p. 84 PI. VII f. 27. Pinnul silesiaca 

 Bleisch (according to Grun.). Schisonema Smitliii (Ag.) V. H. Syn. p. 110 PL XV f. 33. 



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

 East Cape! Tasmania! 



N- avenacea connects iV^. viridula with N. rhynchoccphala. 



5. N. viridula KtiTZ (1844). — V. broadly lanceolate, with subrostrate, obtuse ends. L. 0,05 

 to O.it:; B. 0,ui t(i 0,0 i.T mm. Axial area indistinct. Central area large, orbicular. Striai 10 in 

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

 ends. — Bac. p. ^)1 PL XXX f. 47. Grun. A. D. p. 33 PL II f. 35. V. H. Syn. p. 84 PL VII 

 f. 25. Schisoncma Thwaiiesii V. H. Syn. PL XV f. 38, 39. 



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

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



Var. slesviccnsis Grun. (1880). — V. linear-lanceolate, with broad, rostrate ends. L. 0,o.h 

 to O.o.'i; B. 0,009 to 0,011 mm. Strite 8 to 9 in 0,oi mm. — N. sles. Grun. in V. H. Syn. p. 84 

 PL VII f. 28, 29. K virid. f. minor A. S. Atl. XL VII f. 48. V. H. Syn. p. 84 PL VII f. 2(i. 

 Pinnul. silesiaca Fresenius Senckenb. Abh. IV, PL IV f. 27. 



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



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

 0,0.3; B. 0,00;-).') to 0,007 mm. Central area small. Strife 16 to 17 in O.oi mm. 



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



Var. rosfcUafa Kutz (1844). — V. lanceolate, with attenuated, subrostrate ends. L. O.oa to 

 0.005; B. 0,01 mm. Strife 10 to 11 in 0,oi mm. — N. rest KuTZ Bac. p. 95 PL III f. 05. A. S 

 Atl. XLVII f. 27 to 30. N. rhynchoc. v. rosf. 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 rosfcUafa is a transitional form between K. riridnla and N. amphirhynchns var. 

 amphiceros. 



(). N. villpina Kutz (1844). — V. lanceolate, gradually tapering from the middle to the 

 obtuse ends. L. 0,0 9; B. 0,oi4 to O,oif. mm. Axial area very narrow; central area large, orbicular. 

 Strife 10 to 11 in (),oi mm., radiate in the middle, convergent in the ends, coarsely lineate; lineoUe 



