KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 41 



puncta forining undulating longitudinal rows, about 8 in 0,oi mm. — Coccon. gl. Cl. D. Aret. Sea 

 p. 14 Pl. III f. 12. N. sp. A. S. Atl. VI f. 39. N. gl. Grun. Fr. Jos. Land D. p. 55. Petit 

 Cape Horn D. p. 123 Pl. X f. 16, 17 (1888). leon. n. Pl. I f. 28. N. Jcerguelensis Castr. Chal- 

 lenger Voy. D. Pl. XXVIII f. 16 (according to Petit). 



Marine: Greenland! Spitsbergen! Matotschin Scharr! Cape Horn (Petit), Kerguelens Land 

 (Castr.). 



Var. septentrionalis Cl. — V. smaller. L. 0,o4 to O, os; B. 0,o35 mm. Puncta in the median 

 part of the valve scattered or forming short, undulating rows. — A. S. Atl. VI f. 37. 



Marine: Arctic America! Greenland! Spitsbergen! Sea of Kära! Cape Horn (Petit). 



The original figure in D. of the Aret. Sea shews a marginal rim, which I have since found 

 to be occasioned by the zone. There is no rim on detached valves. The var. septentrionalis connects 

 the type with N. algida. 



6. N. Xi Cl. N. Sp. — V. elliptic-lanceolate, with rostrate ends. L. 0,o55 to 0,07.5; B. 0,022 

 to 0,032 mm. Axial area narrow; central large, orbicular. Strise 12 to 13 in 0, 01 mm. radiate 

 throughout. Puncta 12 in 0,oi mm. Among the median strise are some few shorter ones. 



Marine (Mouth of rivers): Sierra Leone (Deby CoU.)! Cameroon! 



7. N. Delta Cl. (1893). • — V. elliptical, with rostrate ends. L. 0,032; B. 0,oi6 mm. Axial 

 area narrow; central orbicular. Strise 12 in 0, 01 mm., radiate throughout, coarsely punctate; 

 puncta 12 in 0,oi mm., equidistant. Among the median strise there are some few shorter ones. — 

 Diatomiste II p. 14 Pl. I f. 10. 



Marine: Ceylon (Weissllog Coll.)! 



8. N. pusilla W. Sm. (1853). — V. elliptical to lanceolate, with more or less distinctly 

 rostrate ends. L. 0, 03 to 0,047; B. 0, 01.5 to 0,025 mm. Axial area narrow; central area small, 

 orbicular. Terminal fissures in the same direction. Strise 13 to 18 in 0,oi mm. radiate throughout, 

 in the middle of unequal length; puncta distinct, 16 to 20 in 0, 01 mm. — B. D. I p. 52 Pl. XVII 

 f. 145. V. H. Syn. p. 99 Pl. XI f. 17. N. tumida var. genuina Grun. Verh. 1860 p. 537 Pl. IV 

 f. 43 a; v. suh.^alsa Grun. f. b. c. — N. pus. var. spitshergensis Grun. A. D. p. 40 (Cl. M. D. N:o 158). 



Fresh or slightly brackish water: Spitsbergen (Grun), England! Arctic America! Mouth of 

 Jenissey! Bahamas! Surinam! Tasmania! Cameroon! 



Var. lanceolata Grun. (1860). — Lanceolate, with slightly or scarcely rostrate ends. L. 0,04; 

 B. 0,0 15 mm. Striaj 11 in 0,oi mm. — A. D. p. 40 Pl. II f. 47. N. gastroides Greg. M. J. III 

 p. 40 Pl. IV f. 17 (1854). K pulchra Greg. T. M. S. IV p. 42 Pl. V f . 7 (1856). N. tumida v. 

 lanceolata Grun. Verh. 1860 p. 537 Pl. IV f. 44. N. tum. v. subsalsa Ströse Klieken f. 10. 



Brackish water: Germany, Bei-lin (Grun.), Klieken, foss. (Ströse), Sweden, Lysekil! Hungary, 

 Neusiedlersee (Grun.), Mouth of Jenissey! 



Var. jamalinensis Grun. (1880). — V. lanceolate with broad rostrate ends. L. 0,04; B. 0,oi6 

 mm. Central nodule incrassate around the median pores. Strite 13 in 0,oi mm. — A. D. p. 40 

 Pl. II f. 48. 



Brackish water: Sea of Kära (Grun). 



9. N. Demerarae Grun. (1893). — V. broadly lanceolate, with acute or obtuse ends. L. 0,o4 6 

 to 0,085; B. 0,017 to 0,03 mm. Axial area narrow or indistinct. Central area large, irregular, 

 with one, or a few, larger puncta near the central nodule. Terminal fissares in contrary direction. 

 Strise 15 to 17 in 0, 01 mm. somewhat closer near the ends, radiate, punctate; puncta 19 in 0, 01 mm. 

 Median strise of unequal length, terminal strise parallel. — Diatomiste II p. 14 Pl. I f. 9. 



Fresh water: Demerara Eiver! Surinam (Kinker Coll.)! 



10. N. delawarensis Grun. (1893). — V. elliptic-lanceolate, with subrostrate ends. L. 0,085 

 to 0,1; B. 0,044 mm. Median line with distant central pores. Axial area narrow. Central area 



K. Vet. Atad. Handl. Band 27. N:o 3. 6 



