The Botany of Iceland - 01.12.1916, Qupperneq 21

MARINE DIATOMS FROM THE COASTS OF ICELAND
365
Achnanthes Bory.
Subgenus Microneis Cleve 1895. Cl. Syn., 11,187.
Achnanthes Hauckiana Grun. Cl. Syn., 11,190; V. H. Syn., Tab.
XXVII, íigs. 14—15.
Isafjörður (N.W.), C. H. 0.
Area: Eur., Am., Aust.
Achnanthes islandica sp. nov. Tab. nost., íig. 12.
Long.: 24 /1, lat: 9,5 /t, str., utrisqve in valvis, 12 in 10 /i, punctatis.
Epitheca: Valva elliptice-lanceolata, area apicali angusta, media
in valva posita.
Hypotbeca: Valva elliptica. Striis ut in epitheca, parallelis,
apices versus tamen leniter radiantibus, media in parte valvæ fas-
ciam transapicalem satis latam relinqventibus.
Stykkishólmur (S.W.) H. Js.
In am not sure of tlie place of this small form within tlie Achnan-
theae. It scarcely belongs to tlie form-series of Achn. brevipes. Perhaps
it is more closely allied to Achn. hungarica (CI. Syn., II, 190. V. H. Trt.,
tab. VIII, fig. 328). It has been found in a sample, also containing fresh-
water species, an occurrence not rare in the samples from the coasts of
Iceland, examined by me.
Subgenus Achnanthidium (Ktz. 1844) Heib. 1863. Gl. Syn., 11,191.
Achnanthes brevipes Ag. var. tupica Cl. Cl. Syn., II, 193; V. H.
Trt., Tab. VIII, fig. 324.
24 samples (S. 4, S.W. 7, N.W. 4, N. 7, E. 2),
Area: Ubiquist, Grl.. A. S.
Achnanthes brevipes Ag. var. intermedia Ivtz. Cl. Syn., II, 1. c.;
V. H. Trt., Tab. VIII, fig. 325. (A. subsessilis.)
29 samples (S. 5, S.W. 7, N.W. 3, N. 11, E. 3).
Area: Ubiquist, Grl., A. S.
Achnanthes brevipes Ag. var. linearis 0st. 0st. K. D., 330, Tab.
II. fig. 9.
Reykjavik (S.W.), H. Js.
Area: Grl.
Achnanthes brevipes Ag. var. parvula Ktz. Cl. Syn., II, 1. c.;
V. H. Trt., Tab. VIII, fig. 326.
30 samples (S. 2, S.W. 19, N.W. 2, N. 4, E. 3).
Area: Eur., Am, Grl.
In a sample from Kolbeinsá (N.) H. Js. I have found an Achn. brev.
typica, having only ðVí str. in 10 p, an uncommonly wide striation, and
in a sample from the same locality (H. Js.) I have also found the short