MARINE DIATOMS FROM THE COASTS OF ICELAND 365 



Achnanthes Bory. 

 Subgenus Microneis Gleve 1895. Cl. Syn., II, 187. 



Achnanthes Hauckiana Grun. Cl. Syn., 11,190; V. H. Syn., Tab. 

 XXVII, figs. 1415. 



IsafjorSur (N.W.), C. H. O. 

 Area: Eur., Am., Aust. 



Achnanthes islandica sp. nov. Tab. nost., fig. 12. 



Long.: 24/<, lat: 9,5 ,, str., utrisqve in valvis, 12 in 10/, punctatis. 



Epitheca: Valva elliptice-lanceolata, area apicali angusta, media 

 in valva posita. 



Hypotheca: Valva elliptica. Striis ut in epitheca, parallelis, 

 apices versus tamen leniter radiantibus, media in parte valvse fas- 

 ciam transapicalem satis latam relinqventibus. 



Stykkisholmur (S.W.) H. Js. 



In am not sure of the place of this small form within the Achnan- 

 theae. It scarcely belongs to the form-series of Achn. brevipes. Perhaps 

 it is more closely allied to Achn. hungarica (Cl. 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. Cl. Syn., 11,191. 



Achnanthes brevipes Ag. var. typica 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 Ktz. Cl. Syn., II, I.e. ; 

 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. parvala Ktz. Cl. Syn., II, I.e.; 

 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 Kolbeinsa (N.) H. Js. I have found an Achn. brev. 

 typica, having only 5 1 /* str. in 10 //, an uncommonly wide striation, and 

 in a sample from the same locality (H. Js.) I have also found the short 



