The Botany of Iceland - 01.12.1928, Side 81

THE AERIAL ALGÆ OF ICELAND
405
f. 2. E. Icel. L. 40, L. 92, L. 121 — N. Icel. L. 179, L. 253 — N. W. Icel.
L. 268 — W. Icel. L. 307, 309a, 321 - S. lcel. L. 295, L. 353, 381.
f. 3. E. Icel. 41, L. 68 — N. Icel. L. 184, 217, 218,
L. 241.
f. 4. Vestmannaeyjar L. 399, L.401, L. 408, L. 409.
f. 5. Vestmannaeyjar L. 399, L. 400, L. 408.
f. 6. E. Icel. 69.
Thus, taken as a whole, the species lias
been found in nearly all parts of the country
and in very diverse localities, in the highlands
as well as the lowlands, on mineral ground as
well as on ground more or less rich in manure
near human habitations, and íinally also at the
hot springs. Of the individual formæ f. 1 and
f. 2 are the commonest, they often occur together
and in just as diverse localities as the species
as a whole. F. 3 was found parth7 on damp
rock, partly near hot springs; but it is not certain
whether these localities are its peculiar habitat.
F. 4 and f. 5 were only found on the rocks on
the shore of the Vestmannaeyjar, at a considerable
height (20—50 m) above the sea, it is true, though
not quite beyond its influence perhaps. The rocks
were inhabited bj' numerous sea birds whose
droppings no doubt contributed to produce the special life conditions
in this place.
Sl § É CLd í 1
il C= i ! CC: CT:
§§ c== cgf %
i, e C3
Fig. 24. Pinnularia inter-
media Lgst.
a, f. 1; b, c, f. 2; d, f. 3;
e, f. 4; f,f. 5; g, f. 6.
(X 1200).
Pinnularia interrupta W. Sm. f. minor n. f. Fig. 25.
N. Icel. 215, 218 — W. Icel. 338 — S. Icel. L. 364, L?295.
L. 22—30/t, br. 4,8—6//, str. 14 in 10/t. Valve linear,
rostrate-subcapitate, apical area narrow, transapical fascia
present The striæ radiate in the middle, converging
strongly at the apices. Approaches P. subcapitata from which,
however, it differs distinctly by its finer, more radiate, and
converging striation. Especially it shows close affinity to
iV. Hilseana Janiscli (A. S. Atl. T. 45, fig. 65), which is referred
by Cleve (Syn. II, p. 75) to P. subcapitata. Stockmayer
(1909 p. 85) has likewise found specimens intermediate
between P. interrupta and P. subcapitata. The occurrence of
such intermediate forms was already mentioned byCleve
(Syn. II p. 76).
4 of the above-mentioned samples were collected near hot springs,
the 5th (No. 295) on the »hlað« by a farm.
Fig. 25.
Pinnularia
interruplu
W. Sm.
f. minor n. f.
(X 1200).
Pinnularia lata Bréb. var. Rabenhorstii Grun. Cl. Syn. II, p. 81. Grun.
1860, p. 515, Pl. IV, f. 13.
E. lcel. 24, L. 68, L. 69, L. 70, L. 129 - S. Icel. 294.
The Botany of Iceland. Vol. II.
27