KONGL. SV. VET. AKADBMIENS HANDLINGAR. BAND 27. N:0 3. 31 



65. N. inflexa Greg. (1856). — V. narrow, elliptic-lanceolate, with obtuse, conical ends. 

 L. 0,033 to 0,045; B. 0,oo75 to 0,0085 mm. Axial area indistinct, central area small, rounded. Strife 

 11 in 0,01 mm. strongly radiate throughout, distinctly lineate; lineolte 23 in 0,oi mm. — Finn, 

 inflexa Geeg. T. M. S. IV p. 48 PL V f. 20. N. inflexa Donk. B. D. p. 54 PL Vm f. 2. A. S. 

 Atl. XL VI f. 69, 70. 



Marine: Sea of Kara! North Sea! 



N. inflexa v. Biharensis Pant. II p. 48 PL III f. 36 from Bremia seems to be another 

 species, as it has scarcely any resemblance to N. inflexa. 



66; N. northumbrica Donk. (1861). — V. very convex, narrow lanceolate, with acute ends. 

 L. 0,046 to 0,076; B. 0,oo8 to 0,01 mm. Axial area indistinct; central area small, rounded. Striae 

 10 to 11 in 0,01 mm. (the median stronger and more distant) very slightly radiate in the middle 

 transverse at the ends, lineate; lineolse 25 in 0,oi mm. Frustule quadrate. — Donk. M. .1. I p. 9 

 PL I f. 5. B. D. p. 54 PL VIII f. 1. A. S. XLVII f. 19, 20. 



Marine: North Sea! 



This species is remarkable for the extreme convexity of its valves, from which cause it is 

 very difficult to find a specimen in the valvular view. 



67. N. (Khoiconeis) Cubitus Temp. a. Brun (1889). — V. very convex, linear-lanceolate 

 with acute, excavate ends. L. 0,09 to 0,095; B. 0,oi3 mm. Axial area indi.stinct. Central area 

 a narrow, transverse fascia, arising from the two distant median striae. Terminal areas large, 

 triangular spaces (visible only in the zonal view). Striae 6 in 0,oi mm., parallel, coarsely lineate; 

 lineolae 21 in 0,oi mm. Frustule arcuate. — D. foss. du Japon p. 42 PL V f. 8. 



Marine: Japan, fossil! 



68. N. Zostereti Grun. (1860). — V. slightly convex, narrow lanceolate, subacute. L. 0,0 6 5 

 to 0,14; B. 0,011 to 0,022 mm. Axial area indistinct; central area very small, orbicular. Striae 

 7 in 0,01 mm. (a little more close towards the ends) transverse, and slightly curved, lineate; lineolae 

 23 in 0,01 mm. — Verb. 1860 p. 528 PL IV f. 23. A. S. Atl. XLVII f. 42, 43, 44. 



Marine: Adriatic (Grun.), Bab el Mandeb! Ceylon! Labuan! Java! China! Japan (Atl.), 

 Sandwich Islands (Atl.), Brazil (Atl.), Atlantic City, fossil! 



Var. seychellensis Cl. — L. 0,065; B. O,oii mm. Striae 12 in 0,oi mm. 



Marine : Seychelles (Van Heurck Coll.) ! 



N. Zostereti is very similar to iV^. directa, but has more convex valves and slightly radiate, 

 striae curved towards the ends, finely lineate. 



69. N. spuria Cl. N. Sp. — V. rarrow, lanceolate, acute. L. 0,09 to 0,15; B. O.013 to 0,o2i 

 mm. Axial area indistinct. Central area small, irregularly rounded. Striae 7 in 0,oi mm., slightly 

 radiate in the middle, transverse at the ends, coarsely lineate; lineolae 21 to 24 in 0,oi mm. 



Marine: Mediterranean Sea (Gulf of Naples)! Adriatic! New Caledonia (Kinker Coll.)! Gala- 

 pagos Islands (Weissflog Coll.)! 



Var. asymmetrica Cl. — Axial area narrow, unilateral. Striae on the side opposite to the 

 axial area, crossed by an irregular, narrow lateral area. L. 0,15; B. 0,022 mm. Striae 6 in 0,oi 

 mm., lineolae 27 in 0,oi mm. 



Marine: Hungary, fossil (Karnaud Deposit in Deby Coll.)! 



N. spuria resembles N. directa, from which it differs by its slightly radiate striae, and 

 N. pennata, from which it differs by its small central area. From N. Zostereti it may be distin- 

 guished by its coarsely lineate striae and from N. distans by its indistinct axial area. 



70. N. fortis Greg. (1856). — V. very convex, elliptic- to rhombic-lanceolate, obtuse. L. 0,o5 

 to 0,089; B. 0,01 to 0,017 mm. Axial area indistinct; central area small, orbicular. Striae 8 to 9 

 in 0,01 mm. slightly radiate in the middle, transverse at the ends, Coarsely lineate; lineolae 24 in 



