The Botany of Iceland - 01.12.1928, Qupperneq 60

384
JOHS. BOYE PETERSEN
Caloneis fasciata var. elliptica n. var.
The valve elliptic with slightly radiating striæ. L. 18 p,
br. 7 fi, str. 23 in 10 fi. Inside the margin a rather distinct
apical line is seen on either side. Fig. 8.
N. Icel. 215, 217.
pjg 8 Both the samples in which this variety was found were
Caloneis derived from the basalt ravine Stóra Gjá on the eastern side
fasciaia of Mvvatn in which a hot spring debouclies. One sample is
(Lagerst.) Cl. from [|ie surface of mud, thus from a very damp locality,
n var whereas the other is from a large stone which was covered
(X 1200). with Prasiola crispa and mosses intermixed with smaller algæ.
— — var. fonticola (Grun.) Navicula fonticula Grun.
Van Heurck Syn. Pl. 12, íig. 32. Fig. nostr. 9.
N. Icel. 217 - W. Icel. 321.
In this variety the valve is slightly lanceolate with
parallel, or in the longer spccimens slightly radiating, stria-
tion. L. 17,6—20,9 fi, br. 4,5 fi, str. 23 in 10 fi.
The two samples in which it was found were both
derived from the vicinity of a hot spring, one of them
from the same large stone in Stóra Gjá where also var.
elliptica was found, the other from the ground beside the
outflow from »Skrifla« near Reykholt, where it was living
among Hepaticæ.
— — f. acuta n. f.
The valve linear with cuneate pointed apices. Apical area
most fre([uentlv rather broad. L. 17—22 /<, br. 4—5 p, str. 23—
25 in 10 fi. Fig. 10.
E. Icel. 61, 68 - N. Icel. 217, 254.
Fig. 10.
Caloneis in all 4 samples the Diatoms were found among mosses.
None of thein originate from places in which it may be sup-
f acula n f Posed that large quantities of nitrogenous nourishment may
(X 1200). have been present.
-----var. lenticularis 0str.
0strup 1901,]). 261, lig. 29. Navicula fontinalis Boye Petersen 1915,
p. 286, íig. 4.
E. Icel. L. 8, L. 129 - N. W. Icel. L. 268 - S. Icel. 336, L. 364.
In Denmark I have found this form of the alga to be a pronounced
aérial alga, morc especiallv on cultivated soil. The Icelandic samples are
derived partly from a rocky wall (basalt), partly from soil, inter alia
from the vicinity of a hot spring. For No. 268 see under Achnanthes
pygmæa (p. 380).
Fig. 9.
Caloneis
fasciata
(Lagerst.) Cl.
var. fonlicola
(Grun.)
(X 1200)