KONGL. SV. VET. AKADRMIKNS IIANDLINGAR. HANI) 27. N:() 3. 25 



in 0,0 1 mm., radiate tlironghoiit, finely liiieate, the inediaii alternately longer and shorter. — 

 Atl. XLVr f. IT). 



Fresh water: Fort Ludlow (Atl.), Shasta ('o. Calif., fossil! Oregon! Minnesota (intei-glacial 

 deposit)! 



39. N. valida Cl. a. Grun. (1880). — V. slightly asymmetrical, elliptic-lanceolate. L. 0,i)r,7 

 to 0,1 i; B. 0,022 to (),()2t; mm. Axial area narrow, asymmetrical. Central area irregular, .some- 

 what a.symmetrical. Sti'isc 7,.'-. to 8 in 0,01 mm., distinctly lineate, radiate throughout, the median 

 alternately longer and shorter. — A. I), p. 32 PI. 11 f. 21». C'l. Vega p. 4(5(5. 



Marine: Sea of Kara! Cape Wankarema! 



Var. minnfa Cl. (1883). — L. 0,()2r. ; E. 0,(11:5 mm. Stria- 8 in O.m mm., not alternately 

 longer and shorter. — Vega p. 4(5(5. 



Marine: (Jape Wankarema! 



Var.? rapcns'is Cl. — L. Co.'-.fi; B. 0,019 mm. Striee 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. Gastrvm var. Jenisseyensis but has more distinctly 

 lineate striae. The var. rapensis 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,o7 to 0,09; B. 0,oi.') 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?: Kopecz, Hungary, fossil (Pant.). 



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

 rostrate ends. L. 0,0(15; B. 0,03 mm. Axial ai'ea unilateral, narrow. Central area small. Striae 

 8 in 0,01 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. mandosa Donk. 



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

 B. 0,0 15 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. Leudngni (X. Vega p. 505 PI. XXXVI f. 22 (1883). 



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



43. N. (Rhoiconeis) geunflexa KiiTZ (1844). — V. convex, elliptic-linear, with obtu.se ends. 

 L. 0,02 to 0,04. s; B. 0,004 to 0,005 mm. Axial area indistinct. Central area small, orbicular. Striai 

 18 in 0,0 1 mm., a little closer at the ends, radiate throughout. Fru.stule arcuate. L. 0,o2 to 0,o.t; 

 Height 0,0 1 mm. — Bac. p. 101 PI. XXI f. 6. Rhoiconeis cjetmfloxa Grtjn. Verb. 1863 p. 147. 



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



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

 L. 0,045 to 0,095; B. 0,01 to 0,011 mm. Axial area very narrow; central area 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. Verb. 1863 p. 147 PI. IV f. 11. 

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

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



K. Sv. Vet Akaaeiniena Haiullitiifar. Bd 'i7. No 3. 4 



