KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. 18, n:0 5. 5 
Length 0,035 -0,06 mm. Breadth 0,012—0,015 mm. 
Pl. I, fig. 4, a. (dry), 6. (balsam); *°°°/,. 
Brazil, fresh water, collected by Dr. Warminc. (Cx. et Médzx. Diat. N:o 193.) 
In the strongly marked central strie this form reminds one of Navicula Crucicula, 
but it is quite different. There is also some resemblance to the Navicula Lundstrémit 
Ci. (in Cx. et Grun. Arctische Diat. Pl. III, fig. 39). Another allied form is the as 
yet undescribed Cymbella Frivseana Grun. from Tana Elf in Finmarken (Cx. et Moz. 
Diat. N:o 261). This species has produced and capitate ends and 12—15 punctate 
strie in the middle, 18—19 halfway between the middle and the ends, where they are 
21 in 0,01 mm. Length 0,05—0,06 mm. Breadth 0,014 mm. 
2. Cymbella Stodderit Cr. N. Sp. 
Elongate, lanceolate, slightly asymmetrical. Ends slightly produced and attenuated. 
Striea strongly radiant in the middle, almost parallel near the apices, scarcely punctate, 
10 in 0,01 mm. a little more distant in the centre, covering */, of the valve and 
leaving on both sides of the median line a tolerably broad area. 
Length 0,075—0,09 mm. Breadth 0,015 mm. 
Pl. J, fig. 5; *°°°/, (Specimen from Brazil). 
Fossil: Bemis Lake in White Mountains (Mr. Sroppgr). Living: Brazil, Minas 
Geraes on Sphagna leg. Dr. Hs. Mossy. 
This species, which occurs in Cr. et Mézy. Diat. N:o 212 and N:o 274, is most 
nearly related to the C. Americana A. Scum. Atl. Pl. IX, fig. 15 and 20, but the latter 
form has a more narrow area and, as fig. 15 shows, punctate strie. 
Pleurosigma W. Sm. 
1. Pleurosigma tortwosum Cr. N. Sp. 
Median line strongly and equally sigmoid. Strie in three sets, oblique 21, trans- 
verse 22 in 0,01 mm. 
Length 0,076 mm. Breadth 0,008 mm. 
Die Lig By 
Balearic Islets (Dr. S6pDERLUND) rare. 
2. Pleurosigma lanceolatum var. cuspidatum Cu. 
Lanceolate with produced apices, symmetrical. Median line straight, the ends 
turned in opposite directions. Strizw in three sets, one transverse (20 in 0,01 mm.) 
and two oblique (22 in 0,01 mm.). 
Length 0,083 mm. Breadth 0,02 mm. 
Pl. I, fig. 7; °°°/,. 6. structure; 7°%,. 
Marine: Port Jackson (Eugenie Exp.). 
The same variety from Newcastle has according to Grunow 20 transverse and 19 
oblique striz in 0,01 mm. Length 0,105 mm. Breadth 0,026 mm. 
