368 ERNST 0STRUP 



Badllaria Grim. 1880. V. H. Trt., 392. 



Nitzschia paradoxa (Gmel.) Grun. V. H. Trt., 392, Tab. XVI, fig. 518. 



Isafj6r5ur (N.W.), C. H. O. 



Area: Eur., Afr., As., Am., Grl., A. S. 



Nitzschia socialis Greg. Cl. & Grun. A. D., 85; V. H. Syn., Tab. 

 LXI, fig. 8. 



9 samples (S. 1, S.W. 3, N.W. 1, N. 3, E. 1). 

 Area: Eur., Afr., As., Am., Grl., A. S. 



Vivaces Grun. 1880. V. H. Trt., 392. 



Nitzschia islandica sp. nov. Tab. nost., fig. 13. 

 Long.: 94//, lat. : 12 ^ str. 19 20 in 10 ,u, punct. car. 6,5 in 10 JLI. 

 Valva late-lineari, media in parte leniter contracta, apices api- 

 culatos versus attenuata. Carina admodum excentrica, sinuata. 

 Kolbeinsa (N.), H. Js. 



I think the somewhat excentric keel qualifies this species to be classed 

 under Vivaces. See also fig. 522 of N. vivax in Per. D. mar., tab. XVI. 



Spathulatce Grun. 1880. V. H. Trt., 393. 



Nitzschia angularis W. Sm. V. H. Trt., 393, Tab. XVI, fig. 521. 



10 samples (S. 2, S.W. 6, N.W. 1 N. 1). 

 Area: Eur., As., Am., Aust., Grl., A. S. 



Nitzschia angularis W. Sm. var. affmis Grun. V. H. Trt. 1. c., Tab. 

 1. c., fig. 522. 



4 samples (S.I, S.W. 2, E.I). 

 Area: Eur., Grl. 



Dissipates Grun. 1880. V. H. Trt. 394. 



Nitzschia dissipata (Ktz.) Grun. var. Acula Hantzsch. V. H. Trt., 

 395, Tab. XVI, fig. 527. (N. v. d. acuta). 



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

 Area: Eur., Aust. 



I have retained the name Acula, as this undoubtedly is the correct 

 one. This form is, as far as I know, first described in Cl. & Gr. A. D. 

 (1880;, pag. 90 under the name of Nitzschia Acula Hantzsch. It is found 

 under the same name as a var. of N. dissipata in V. H. Syn. (1885), pag. 178, 

 and in the text to tab. LXIII, fig. 4. But Acula is everywhere altered 

 to acuta in De Toni Syll. (1892) pag. 527, V. H. Trt. (1899), pag. 395 and 

 in Per. D. mar. (18971908), pag. 281. If Acuta, by Hantzsch or Grunow, 

 has been considered an error in writing, I do not know, but Acula is 

 however, perhaps not a particularly good Latin word, meaning a small 

 needle (see Arnesen: Ny latinsk Ordbog, Kjobenhavn 1848, pag. 56) 

 but the term is very apposite to the variety in question. 



