VEGA-EXPEDITIONENS VETENSKAPLIGA ARBETEN. 469 
convex valve 9 in the middle, 10 in 0,01 mm. toward the ends, 
reaching almost to the median line; on the concave valve 83— 
10, on one side of the valve not reaching the median line, 
on the other reaching the median line, but interrupted by a 
linear area. 
Length 0,06 mm. Breadth 0,02 mm. — P1. 36, fig. 23. 
Cape Wankarema. 
var. elliptica Cl. Valve elliptie. Strix parallel, 10 in 0,j01 
mm. Length 0,065 mm. Breadth 0,02 mm. — Pl. 36, fig. 24. — 
Cape Wankarema. : 
The concave valve of this variety is scarcely different 
from N. incudiformis Grun. 
N. (Rhoikoneis) obtusa CI. N. Sp. (Rhoie. obtusa CI. in CI. 
& Möll. Diat. 315—318) Elongated, linear, with rounded obtuse 
ends. Strie curved, not parallel, very faintly lineate, on one 
half of the valve reaching the median line, on the other end- 
ing at some distance, irregularly interrupted, 11 in 0,01 mm. 
Length 0,075 mm. Breadth 0,014 ram. — P1. 36. fig. 25. — Cape 
Wankarema. 
N. (Rhoikoneis) Bolleana Grun. (Verh. 1863, pag. 147, Pl. 
XIII, fig. 11) Greenl., Spitsb., Finm., Kara (Matotschkin), Cape 
Wankarema. 
Specimens from Greenland have 8 radiant strie in 0,01 
mm. in the middle, 12 near the ends. Specimens from Wan- 
karema are less arcuate, have in 0,01 mm. 10 strie, which are 
almost parallel. The strie are transversely finely lineate as in all 
species of the directa-group. Mr. Grunow has named this variety 
from Wankarema Eh. Bolleana var.?  Siberica (Cl. & Möll. Diat. 
No 302.) — Pl. 37, fig. 38. — Another variety from Cape Wanka- 
rema has asymmetric striation and 11 stri&e in 0,01 mm. var. 
asymmetrica CI. length 0,045 mm. breadth 0,01 mm. PI. 37, fig. 39. 
N. kariana Grun. (A. Diat. pag. 39, Pl. II, fig. 44) Kara, 
F. J. L., Cape Wankarema. 
a. gemuna Strie 12—14 in 0,01 mm. Length 0,085 mm. 
Breadth 0,026 mm. — Kara, F. J. L., Cape Wankarema. 
2. detersa Grun. Mpt. Strie interrupted on both sides of 
the median line by more or less broad areas. Length 0,09 
mm. Breadth 0j024 mm. — Kara, F. J. L., Cape Wankarema. 
— PI. 36, fig. 36. 
7. minor Grun. (ÅA. D. pag. 5. N. frigida (irun. A. D. pag. 
39) Strix 16—18 in 0,01 mm. Length 0,044—0,07 mm. Breadth 
0,012—0,013 mm. — Kara, F. J. L. ; 
