KONGL. 8V, VET. AKADEMIENS HANDLINGAB. BAND. 27. N:0 3. 29 



Var.? subimpressa Gbun. (1880). — V. lanceolate. L. 0,o65; B. 0,oi6 mm. Striae 11 to 12 

 in 0,0 1 mm., crossed by a longitudinal line. — N. subimpr. Grun. A. D. p. 39 PI. II f. 45. 



Marine: Sea of Kara (Grun.). 



Var.? tenuis Cl. (1883). — V. elliptic-lanceolate, with a longitudinal impression on both 

 sides of the median line. L. 0,o."i8; B. 0,oi5 mm. Striis 18 in 0,oi mm., unilaterally interrupted 

 by a narrow transverse fascia. — N. subimpressa var. tenuior Cl. Vega D. p. 470 PI XXXVII f. 49. 



Marine: Cape Deschneff! 



58. N. irregularis Pant. (1889). — V. narrow, lanceolate, with subacute ends. L. 0,i26; 

 B. 0,021 mm. Axial area broad on one side of the median line, narrow on the other. Striis 7 

 to 10 in 0,01 mm. almost parallel, alternately longer and shorter, on one side of the median line 

 crossed by a linear lateral area. — Pant. II p. 49 PI. XXX f. 424. 



Marine: Hungary, fossil (Pant.). 



I have not seen this species, but to judge from the figure it seems to be akin to N. trunsi- 

 tans var. asymmetrica. Somewhat similar is N. primordialis Pant. (Ill PI. XXV f. 382). 



59. N. (Rhoiconeis) siMrica Grun. (1882). — V. lanceolate, subacute. L. 0,o4 to 0,o6; 

 B. 0,0 1 mm. Axial area indistinct; central area large, subquadrate. Striae 10 (at the ends 10 to 

 11) in 0,01 mm. almost parallel throughout, distinctly lineate. Frustules arcuate, with narrow 

 connecting zone. — Rhoiconeis Bolleana var.? sibirica Grun. in Cl. M. D. N:o 302. Cl. Vega 

 p. 469 PI. XXXVn f. 38. 



Marine: Cape "Wankarema! 



Var. asymmetrica Cl. 1883. — Axial area unilateral, narrow. Striae 11 in 0,oi mm. — 

 N. Bolleana v. asym. Cl. Vega p. 469 PI. XXXVII f. 39. 



Var. mediterranea Cl. — V. narrow, rhombic-lanceolate acute. L. 0, i; B. 0,oi3 mm. Central 

 area rounded. Striae 7 in 0,oi mm., distinctly lineate; lineolae about 27 in 0,oi mm. 



Marine: Gulf of Naples! 



N. sibirica resembles N. Bolleana, but differs by its more parallel striae and by the narrow 

 connecting zone. The N. Zostereti A. S. N. S. D. Ill f. 3 seems to belong to N. sibirica. 



60. N. (Bhoicoueis) superba Cl. (1883). — V. rhomboidal with subacute ends. L. 0,o6; 

 B. 0,0 2 mm. Axial area unilateral, more or less narrow. Central area small, somewhat trans- 

 verse. Striae 8 to 10 in 0,oi mm., parallel, finely lineate, frequently crossed, on one side of the 

 median line by an irregular, narrow lateral area. — Vega p. 468 PI. XXXVI f. 23. 



Marine: Cape Wankarema! 



Var. elliptica Cl. (1883). — V. elliptical. L. 0,o6 5; B. 0,o2 mm. Striae 10 in 0,oi mm. 

 Marine: Cape Wankarema! 



The valves of this species seem to be somewhat dissimilar, the concave having more distant 

 striae, frequently crossed unilaterally by a narrow area. 



61. N. (Rhoiconeis) obtusa Cl. (1882). — V. linear with broad, rounded ends. L. 0,o5.5 to 

 0,07 5; B. 0,014 to 0,018 mm. Axial area narrow, unilateral, irregular. Central area small. Striae 

 11 in 0,01 mm., slightly radiate in the middle, and convergent at the ends, frequently crossed 

 by irregular longitudinal, narrow bands. — Cl. a. M. D. N:o 315 to 318. Cl. Vega p. 469 

 PI. XXXVI f. 25. 



Marine: Cape Wankarema! 



62. N. ammophila Grun. (1882). — V. linear-lanceolate, subacute. L. 0,oi7 to 0,03; B. 0,oo5 

 mm. Axial and central areas indistinct. Striae 10 to 11 in 0,oi mm., finely lineate, in the 

 middle subradiate, at the ends transverse (12 to 13 in 0,oi mm.). — F. D. Ost. Ung. p. 149 

 PI. XXX f. 66 to 69. 



Marine and brackish: Coasts of England and Sweden (Grun.), Hungary, Tallya, fossil (Grun.). 



