277 



Heteroneis Cl. Syn. II, p. 182. 



148. Achnanthes gibberula Grun., V. H. Syn. Uih. XXVII, figs. 

 47- 49. 



Kirkebokamp (S trom 6). 



149. A. Liljeborgii Grun., Le Diatomiste II tab. III, fig. 19. 



Plankton from Sorvaagsvatn (Vaago. Onlj^ one example 

 of the epitheca was found. As it does not exactly correspond 

 to the above-mentioned figure of Cleve I have given a ligure 

 of it in fig. 43 i^^Vi). Kig. 43. 



Microneis Cl. Syn. II, p. 187. 



150. Achnanthes minutissima Kiitz., V. H. Syn. tab. XXVII, figs. 

 35—38. 



Var. cpyptocephala Grun., V. H. 1. c, figs. 41 — 44. 



The main species as w^ell as the variety are rather common in 

 many of the gatherings. In one gathering from Ornefjæld i Sy der 6) 

 the var. cryptocephala occiirs most frequently. 



151. A. linearis W^. Sm. var. pusilla Grun., V. H. Syn. tab. 

 XXVII, fig. 33. 



Thorshavn (S t r 6 m 6). 



152. A. delicatula Kiitz., V. H. Syn. tab. XXVII, figs. 3—4. 

 Midvaag (Vaago); Trangisvaag (Sy der 6). 



Achnanthidium (Kiitz. 1844) Heib. 1863. Cl. Syn. II, p. 191. 



153. Achnanthes lanceolata Bréb., V. H. Syn. tab. XXVII, figs. 



8—11. 



Not rare in many of the gatherings. Occurs abundantly in a gathering 

 labelled: »Algæ in slowly running water near Bosdalafos« (Vaago). 



Var. Færoensis m. Fig. 44 ^^^ji. 



L. c. 0,03 mm., B. 0,007—0,008 mm. Striæ aboiit 

 12 in 0,01 mm. 



Valves narrow, lanceolate ; epitheca wilh horseshoe- 



like mark ; hypotheca with transapical fascia nearly 



reaching the margin. Otherwise both the valves of Fig. 44. 



about the same form and size. 



Not rare in some of the gatherings. Occurs rathcr abundantly 

 in a gathering labelled: »Algæ in slowly running water near Bosdalafos« 

 (Vaago). 



