KONGL. SV. VET. AKADEMIENS HANDLINGAU, HANI) 27. N:o 3. 41 



puncta forming undulating longitudinal rows, about )S in (),oi mm. — Coccon. gl. Cl. I). Arct. Sea 

 p. 14 PL III f. 12. N. sp. A. S. Atl. VI f. 89. N. (/l. Grun. Fr. Jos. Land D. p. 55. Petit 

 Cape Horn D. p. 123 PL X f. 16, 17 (1888). Icon. n. PL I f. 28. N. Icrnfuelensis Castr. (Chal- 

 lenger Voy. 1). PL XXVIII f. 16 (according to Petit). 



Marine: Grreenland! Spitsbergen! Matotscliin Scliarr! Cape Horn (Petit), Kerguelens Land 

 (Castr.). 



Var. septentrionalis Cl. — V. smaller. L. 0,04 to 0,0.5; B. 0,o3 5 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 Kara! Cape Horn (Petit). 



The original figure in D. of the Arct. 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. sepfentrionaUs connects 

 the type with N. algida. 



6. N. Xi Cl. N. Sp. — V. elliptic-lanceolate, with rostrate ends. L. 0,or>5 to 0,o7r); B. 0,022 

 to 0,03 2 mm. Axial area narrow; central large, orbicular. Striai 12 to 13 in 0,oi mm. radiate 

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



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



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

 area narrow; central orbicular. Strife 12 in 0,oi mm., radiate throughout, coarsely punctate; 

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

 Diatomiste II p. 14 PL I f. 10. 



Marine: Ceylon (Weissflog ('oil.)! 



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

 rostrate ends. L. 0,03 to 0,047; B. OjOi.^) to 0,o25 mm. Axial area narrow; central area small, 

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

 in the middle of unequal length; puncta distinct, IG to 20 in 0,oi mm. — ^ B. D. I p. 52 PL XVII 

 f. 145. V. H. Syn. p. 99 PL XI f. 17. N. tumida var. genuina (jrun. Verh. 1860 p. 537 PL IV 

 f. 43 «; V. suhsalsa Grun. f. h. c. — N. pus. var. spifshergensis Griw. 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,o4 ; 

 B. 0,015 mm. Striaj 11 in 0,oi mm. ~ A. D. p. 40 PL II f. 47. N. gastroides Greg. M. J. Ill 

 p. 40 PL IV f. 17 (1854). N. pidchra 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. turn. v. suhsalsa Strose Klieken f. 10. 



Brackish water: Germany, Berlin (Grun.), Klieken, foss. (Strose), Sweden, Lysekil! Hungary, 

 Neusiedlersee (Grun.), Mouth of Jenissey! 



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

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

 PL II f. 48. 



Brackish water: Sea of Kara (Grun). 



9. N. Demerarae Grun. (1893). — V. broadly lanceolate, with acute or obtuse ends. L. 0,046 

 to 0,08 5; B. 0,0 17 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 fissures in contrary direction. 

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

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



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



10. N. delawarensis (trux. (1893). — V. elliptic-lanceolate, with subro.strate ends. L. 0,o85 

 to 0,1; B. 0,0 4 4 mm. Median line with distant central pores. Axial area narrow. Central area 



K. Vet. Akad. Haadl. Band 27. N:o 3. 6 



