KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND I8. n:o 5. 11 
This small species seems to be the unnamed form in A. Scumipts Atlas Pl. 46, fig. 7 
and is perhaps according to Grunow the N. mediterranea Kitz. Bac. Pl. II, fig. XVU, 
which however is represented on much too small a scale to admet of identification. 
Another allied form is the yet unpublished MN. cotiformis Gruy. from Demerara River, 
which has cuneate ends and 5 strie in 0,01 mm. Length 0,06 mm. Breadth 0,014 mm. 
16. Navicula Anderssonii Cu. N. Sp. 
Linear oblong, with almost cuneate ends. Strie parallel or slightly radiate in 
the middle, 6*/,—7 in 0,01 mm. not reaching the median line, which in surrounded by 
a narrow area, dilated around the central nodule. 
Length 0,075 mm. Breadth 0,019 mm. 
Pl. UI, fig: 28, 7°, 
Gallapagos Islands (Eugenie Exp.). 
I have named this species in honour of the late Prof. N. J. Ayprrsson, botanist 
to the Eugenie Expedition. 
17. Navicula marginulata Cr. N. Sp. ’ 
Rhombic; striz very short, marginal, enclosing a large structureless area, 17 in 
0,01 mm. 
Length 0,042 mm. Breadth 0,012 mm. 
Pl. TH, fig. 20, °",. 
Florida, near the Harbour of Pensacola, in a gathering sent by Mr. Frpicer. 
18. Navicula (Powelli Lewts var.) Gallapagensis Cu. 
Linear oblong with cuneate ends. Strie coarse, almost parallel, 8°/, in 0,01 mm., 
on both side of the median line interrupted by linear areas. There are thus four lon- 
gitudinal series of short stria, two near the margins and two close to the median line, 
interrupted near the central nodule. 
Length 0,05—0,09 mm. Breadth 0,013—0,021 mm. 
Gallapagos Islands (Eugenie Exp.). 
Pl. III. fig. 30. 
Of the true N. Powellii Lewis I have not seen a figure, but Grunow states that 
his N. Vidowichit (Verh. 1863, Pl. IV, fig. 4) is the same species. I have seen the latter 
form in gatherings from Adriatic sea, kindly sent me by Mr. F. Hauck, and I find 
that the form is different, the striae more distant (6 in 0,01 mm.). Length 0,1122 mm. 
Breadth 0,02 mm. NN. Egyptiaca Grev. Trans. Micr. Journ. XIV, p. 127, Pl. 12, fig. 
16—17 seems to be the same, but the strie are stated to be only 4 in 0,01 mm. An- 
other allied form is, as far on may judge from the figure, N. Zanardiniana Grun. 
(Verh. 1860, Pl. 3, fig. 12) with indistinctly punctate strie, 6 in 0,01 mm., in four 
uninterrupted rows. Another, undescribed form is N. Wittii Grun. Mspt. (PI. Il, fig. 
31, °°°/,) from Brazil, which is not so long and slender as the last named species and 
has 8 strie in 0,01 mm: The two following forms are also allied to N. Powellii. 
