KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27, N:0 3. 25 



in 0,01 mm., radiate throughout, finely lineate, the median alternately longer and shorter. — 

 Atl. XL VI f. 15. 



Fresh water: Fort Ludlow (Atl.), Shasta Co. Calif., fossil! Oregon! Minnesota (interglacial 

 deposit)! 



39. N. valida Cl. a. G-run. (1880). — V. .slightly asymmetrical, elliptic-lanceolate. L. 0,o.5 7 

 to 0,11; B. 0,022 to 0,026 mm. Axial area narrow, asymmetrical. Central area irregular, some- 

 what asymmetrical. Striffi 7,5 to 8 in 0,oi mm., distinctly lineate, radiate throughout, the median 

 alternately longer and shorter. — A. D. p. 32 PI. II f. 29. Cl. Vega p. 466. 



Marine: Sea of Kara! Cape Wankarema! 



Var. minuta Cl. (1883). — L. 0,02.5; B. 0,01.3 mm. Striae 8 in 0,oi mm., not alternately 

 longer and shorter. — Vega p. 466. 



Marine: Cape Wankarema! 



Var.? capensis Cl. — L. 0,05 6; B. 0,oi9 mm. Striae 8 in 0,oi mm. not distinctly lineate^ 

 radiate throughout. Axial area symmetrical. Central area larger. 



Marine: Cape of Good Hope! 



The type is most nearly akin to N. Gastrum var. Jenisseyensis but has more distinctly 

 lineate striae. The var. capensis is very doubtful as a form of N. valida. 



40. N. Hasta Pant. (1893). — V. lanceolate, gradually tapering from the middle to the 

 subacute ends. L. 0,07 to 0,09; B. 0,oi5 mm. Axial area narrow, slightly dilated in the middle. 

 Striae 9 in 0,oi mm. strongly radiate throughout and coarsely lineate. Among the median striae 

 some few shorter ones are intercalated. — Pant. Ill PI. V f. 74; PI. XIV f 213. 



Habitat?: KSpecz, Hungary, fossil (Pant.). 



41. N. imperfecta Cl. (1883). — V. elliptical to elleptic-lanceolate, frequently with sub- 

 rostrate ends. L. 0,065; B. 0,o3 mm. Axial area unilateral, narrow. Central area small. Striae 

 8 in 0,0 1 mm. radiate throughout, finely lineate and crossed by several longitudinal and undulating 

 narrow blank bands. — Vega p. 466 PI. XXXVI f. 34. 



Marine: Sea of Kara! Cape Wankarema! 



This form is very nearly akin to N. valida, from which it differs by its striae being 

 divided into 2 to 4 lengths, as the striae of N. maculosa Donk. 



42. N. censors A. S. (1876). — V. narrow elliptic-lanceolate, obtuse. L. 0,o6 to 0,i; 

 B. 0,015 to 0,02 mm. Axial area narrow; central area transverse, rectangular. Striae 8 in 0,oi 

 mm., radiate throughout, finely lineate and crossed by 3 to 4 irregularly undulating, longitudinal 

 bands. — Atl. XLVIII f. 24, 25, 26, 27. N. Leudugeri Cl. Vega p. 505 PL XXXVI f. 22 (1883). 



Marine: Ceylon! Samoa (Atl.), Sandwich Island (Atl.), Singapore (Atl.), Java! 



43. N. (Rhoiconeis) genuflexa KtJTZ (1844). — V. convex, elliptic-linear, with obtuse ends. 

 L. 0,02 to 0,043; .B. 0,oo4 to 0,oo5 mm. Axial area indistinct. Central area small, orbicular. Striae 

 18 in 0,01 mm., a little closer at the ends, radiate throughout. Frustule arcuate. L. 0,02 to O.oa; 

 Height 0,01 mm. — Bac. p. 101 PI. XXI f. 6. Rhoiconeis genuflexa Geun. Verh. 1863 p. 147. 



Marine: Peru (Grun.), New Zealand (Grun.), Port Jackson! Samoa! Labuan! Ceylon! 



44. N. (Bhoiconeis) Bolleana Grun. (1863). — V. linear-lanceolate, with obtuse ends. 

 L. 0,04.5 to 0,09 5; B. 0,oi to 0,oii mm. Axial area very narrow; central ai'ea large quadrate. 

 Striae 8 (middle) to 11 (ends) in 0,oi mm. not distinctly lineate, radiate throughout. Frustule 

 with broad connecting zone, arcuate. — Rhoiconeis Bolleana Grun. Verh. 1863 p. 147 PL IV f. 11. 

 A. S. Atl. XLVII f. 18 (striae strongly punctate)? N. Index Temp. a. Brun D. foss. du Japon 

 p. 44 PL V f . 5 (1889). 



K. Sv. Vet, Akademiens Handlingav. Bd 27. N;o 3. 4 



