BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND. 22. AFD. III. N:0 4. 17 
sä SiS 
= Sal 
ESSER SK ST 
B oa je 
Ås lAsclsta tg? 
S&S I hIS =E S = 
des 
tä | 
Synedra hyperborea var. rostellata GRUN.. . . + : 0 
fRAMassiöstra gravida CL. Vv PIPER ost. + är ar ? 
oNOrdenskiöldiv ChisaMI og BORTA NICE SF + + + 
Thalassiothrix longissima OL. . . . + . - . « + Iisill + + 
Sum 97 | 66 42 65 23 
Percentage | 68 | 43 68 20,1 
The above list shews in a striking manner how few of 
these forms have been found outside the polar basin, 23,7 
percent only. At the east-coast of Greenland as well as at 
Cape Wankarema 68 percent have been found. Almost all 
of them occurred on ice-flakes and it seems very probable 
that the forms found in the sample of Ceratium 'Tripos, 30 
naut. miles from Cape Eglinton, are also derived from molten 
ice, which drifted with the DLabrador-stream. It can hardly 
be assumed that so many litoral forms, among which many 
are extremely small and delicate, may live so far from 
the shore. Besides most species were found in few speci- 
mens only. | 
The great resemblance between the diatoms found on the 
1ce at Cape Wankarema, between Franz Josefs Land and 
Novaja Semlja, and at the east-coast of Greenland and those 
observed in the Labrador-stream, tends to shew that the ice- 
fakes are drifted from Behrings Strait to the north of Green- 
land, where one portion of them continues to drift along the 
east-coast of (Greenland and another with the Labrador-stream. 
Remarks on the forms, indicated in the above list, or 
found sparingly in the plankton. 
Achnanthes polaris ÖESTR. (p. 408 PI. VII f. 36). Frustule 
not genuflexed. V. in length 0,05 and in breadth 0,01 mm., 
lanceolate, gradually tapering from the middle to the some- 
what obtuse ends. Upper valve with narrow and central 
axial area; strige costate, 10 in 0,01 mm., very slightly radiate. 
2 
