140 P. T. CLEVE, SYNOrsLS OF THE NAVICULOIl) DIATOMIS. 



central areas indistinct. Stritc abuut ll! in Oan nun. the median .stronger and more distant, very 

 slightly radiate, at the ends parallel, all tinely punctate. — Staiironcis Crucicida W. Sm. B. D. 

 1 p. 60 PI. XIX f. U)2. Ldt. Spitsh. 1). p. 37" PI. 11 f. 14. N. cmc. Donk. B. D. p. 44 PI. VI 

 f. 14. V. H. Syn. p. 96 PL X f. 15. Siauroneis dilatuta W. Sm. B. ]J. 1. c. f. 101? 



Brackish water: Spitsbergen! Baltic! Coasts of the North Sea (Sweden! England! Belgium 

 V. H.), Atlantic coasts of North America! 



Var. obtusata Grun. (1880). — Smaller, broadly kmceolate, with rounded obtuse ends. L. 

 0,02.") to 0,05; B. 0,0 1 to 0,0 16 mm. Stria- 17 in 0,oi mm. — Xav. Crude, car. obt. Grun. A. L). 

 p. 35 PI. II f. 37. 



Brackish water: Grun. 



Var. miniita Grun. (1860). — V. broadly lanceolate, with slightly rostrate ends. — L. 0,02; 

 B. 0,01 mm. Strict 19 in 0,01 mm. — Sfaur. Criicicnlu rar. minnin Grun. Verh. 1860 p. 567 

 PI. VI f. 15. 



Marine: Adriatic (Grun.). 



7. N. gibbula Cl. N. Sp. — V. linear, slightly gibbous in the middle, with broad, truncate 

 ends. L. 0,o3.3 to 0,043; B. 0,0085 to 0,oi mm. Axial area indistinct. Central area very small, 

 I'ounded. Strife K! (middle) to 21 (ends) radiate in tlie middle, where tliey are of equal length, 

 slightly radiate in the ends, distinctly punctate, puncta (about "2,2 in 0,oi mm.) forming longi- 

 tudinal rows. — N. gibberula Lagst. Spitsb. D. p. 30 PI. J f. 7 (1873). — N. gibbula Icon. n. PI. V f. 17. 



Fresh water (moist earth etc.): Spitsbergen! Beeren Eiland (Ldt.). 



Var. oblonga Lagst. (1873). — V. linear not gibbous in the middle. — Nao. (jibbenda cur- 

 oblonga Lagst. 1. c. p. 31. 



Fresh water: Spitsbergen (Lagst.). 



Var. capitaia Lagst. (1873). — V. strongly gibbous in the middle, with dilated, rounded 

 truncate ends. — N. (jibbtrnlu car. capitata Lagst. 1. c. p. 31 PL I f. 7 a'. 



Fresh water: Spitsbergen (Lagst.), Beeren Eiland (Lagst.). 



8. N. Liindstroniii Cl. (1880). — V. linear-lanceolate, with subrostrate, broad ends. L. 0,034 

 to 0,0.51; B. 0,0 11 to 0,0 13 mm. Median line with the terminal fissures in the same direction. 

 Axial area narrow, slightly dilated around the central nodule. Striro 16 (middle) to 20 (ends) in 

 0,01 mm., radiate throughout, finely punctate, in the middle of equal length. — Cl. A. I), p. 13, 

 36, PL II f. 39. 



Brackish water: Sea of Kara (Jamal)! 



Var. Frieseaini Grun. (1)^79). — V. with broad rostrate-capitate ends, slightly asymmetrical. 

 L. 0,032 to 0.048; B. 0,012 to 0,0 15 mm. Strife 16 to 18 in 0,oi mm. (middle) or 20 to 22 in 0,oi 

 mm. at the ends, in the middle radiate and of eqiial length, at the ends radiate, distinctly punctate, 

 puncta (about 20 in 0,01 min.) forming undulating longitudinal rows. — Cymbella Frieseana Grun. 

 in Cl. M. D. N:o 261. Icon. n. PL V f. 18. 



Brackish water: Finmark (Tana Elf)! 



9. N. protractsi Grun. (1880). — V. linear, with rostrate and truncate ends. L. 0,022 to 

 0,035; B. 0,008 to (»,oi mm. Axial area very narrow; central very small. Strife 12 (middle) to 20 

 (ends) in (),oi mm., slightly radiate in the middle, transverse at the ends, coarsely punctate, puncta 

 about 17 in O.oi mm. - X. Cruc. car.':' prof. Grun. A. D. p. 35 PL II f. 38. " V. H. Syn. p. 96 

 Suppl. PL B f. 27. Foss. D. Oster. Ung. p. 146 PL XXX f. 47. .V. Troglodytes Pant. II p. 54 

 i'l. XI f. 184 (1889)? 



BrackLsh water: Salines of the mainland of Europe (Grun.), Belgium (V. H.), Hungary, 

 foss. (Pant.) — Cameroon! 



Var. maxima Cl. — L. 0,o8; B. 0,oi6 mm. Stria' about 14 to 15 in 0,oi mm. 

 Fresh water: Rio Purus, Brazil (Deby ('oil.)! 



