548 



128. D. exigua (Grun.) Øst. (= DiatomaV exiguum Grun. in 

 Nov. Exp., p. 2, tab. I., tig. 3). 



Ejde (Ostero;; Vestmanhavn, Thorshavn (S trom 6); Midvaag (Vaago); 

 Trold hoved (San do). 



This small species, which I eonsider a true Denticula, is referred 

 doubtfully to Diatomu by Griinow. His specimens are trom the coast 

 of Chile and grew on Lessonia. Along the Færoes it occurs on Ecto- 

 carpus and Cladophora. 



DIATOMA De Cand. 1805, V. H. Syn., p. 159. 



:i T29. Diatoma hiemale (Lyngbye) Heib., V. H. Syn. tab. LI., 



figs. 1—2. 



Gjov, Kalbakfjord (O s ter 6); Thorshavn (S trom 6). 

 Found only as solitar}' specimens. 



FRAGILARIA Lyngbye 1819, V. H. Syn., p. 155. 



130. Fragilaria striatula Lyngbye, W.Sm. Syn. tab. XXXV., lig. 298. 



Very common. Found in 55 gatherings from Bor do; Ostero; 

 Stromo; Vaago; Nol s 6; and Sy de ro. It often occurs in large quan- 

 tities, especially in several of the gatherings from Thorshavn. 



F. striatula Lyngbye var.? californica Grun., V. H. Syn. tab. 

 XLIV., fig. 13. 



Kvi vig (Stromo). 



*131. F. æqvalis Heib. var. producta Lgst. , V. H. Syn. tab. 

 XLIV., lig. 7 b. 



Rare. Kalbakfjord (Stromo). 



132. F. hyalina Grun., V. H. Syn. tab. XLIV., figs. 14—15. 

 Not common. Fuglefjord (Ostero); Vestmanhavn (Stromo). 



133. F. vitrea (Ktz.) Grun., V. H. Syn. tab. XLIV., lig. 16a&b. 



— var. minima Grun., V. H. 1. c, ligs. 

 16 c, d, e, 18. 



Not rare. Found in 17 gatherings from Videro; Ostero: Stromo; 

 Vaago; Nol so; and Sydero. 



The variety minima occurs fully as often as the main species. 



*134. F. lapponica Grun., Øst. Surtarbr. IL, lig. 7. 

 Rare. Vestmanhavn (Stromo). 



PERONIA Bréb. & Arn. 1868, V. H. Tr. d. Diat, p. 333. 



*135. Peronia erinacea Bréb. & Arn., VII. Syn. tab. XXXVI., lig. 19. 

 Kalbakfjord (S t ro m 6). 



