The Botany of Iceland - 01.12.1928, Page 64

388
JOHS. BOYE PETERSEN
Navicula bryophila Boye P. n. sp.
Valva lineari, apicibus rostratis, long. 16,«, lat. 3,7,«, striis
delicatissimis, vix visibilibus circiter 35 in 10/<, radiantibus.
Area apicali angusta. Fig. 13.
E. Icel. 7, 25.
Navicula Found among mosses in two places which were often
Rove°P n7s. damP with trickling water. It is hardly a species that will
°('x 1200)P withstand much desiccation.
The valve is very liyaline and the striæ are so flne that
they are hardly visible and their exact number can scarcely be ascer-
tained. They seem to become closer towards the apices.
Naviculœ mesoleiœ Cl.
Navicula bidentula Boye P. n. sp.
Valva lineari, subcapitata, in medio inflata, utrinque bi-
dendata. Long. 17 fi, lat. 3,5/t, striis invisibilibus. Area api-
cali angusta, area centrali in fasciam transapicalem dilatata.
Fig. 14.
Fig 14.
N. lcel. 215, 217. Navicula
The valve of this small, very peculiar species of which BoyeP^nísp
I have only seen few specimens has the same outline as (x 1200).
N. Lagerstedtii Cl. (Syn. I, p. 141 ; Lagerstedt 1873, Pl. II,
fig. 12), but the striation is so fine in the present species that I have
not been able to count the striæ. There seems to be a transapical
area, and the frustule is much smaller.
Only found in the ravine Stóra Gjá near Mývatn.
Navicula (Caloneis?) Borrichii Bojæ P. var. subcapitata Boye P.
Boye Petersen 1915, p. 285, flg. 3.
E. Icel. L. 121.
Only known as an aérial alga, and only from Denmark. Both there
and in Iceland it was met with under such circumstances that it must be
presumed to make great demands on the nutritious matter of thé earth
and must likewise be supposed to belong to the species that will sur-
vive much desiccation.
-----var. undulata n. var.
Valva lateribus triundulatis, long. 24,«, lat. 5,2 fi, striis
23 in 10 [x. Fig. 15.
N. Icel. 182, L. 241.
This form is identical with a specimen already mentioned
by me (1915, p. 289), as a probable variety of Stauroneis
agrestis Boye P. with which, however, it has no connection.
Fig. 15. I have subsequently, in the preparation in which this speci-
Navicula men occurred, found other specimens seen in girdle view
Borrichii an(j sjlowintj the structure peculiar to N. Borrichii. It was
unduláta n f°und on a turf fence near Skútustaoir and at Uxahver on
var. (X1200). the bank of one of the hot streams.