545 



104. S. investiens W. Sin., V. IL Syn. hil). XL., fig. 3 and 3b,C,d,e. 

 Very common. Found in 53 gatherings from Viderd; Bordo; 



Ostero; Stromo; Vaago; Sando; Store Dimon; and Sydero. 



It occurs fairly often in large quantities completely covering the 



host-plant. 



105. S. affinis Ktz., V. H. Syn. tab. XLI. 



Of the numerous varieties belonging to tliis species I have observed 

 tlic folio wing: — 



S. affinis var. acuminata Grun., V . IL, 1. c, fig. 11. 

 — Arcus Ktz., V. H., 1. c, fig. 11. 



fasciculata Ktz., V. H., 1. c, tig. 15. 



intermedia Grim., V. H., 1. c, fig. 21. 



lancettula Grim., V. H., 1. c, fig. 28. 



obtusa Arnott, V. H., 1. c, lig. 12. 



parva Ktz., V. IL, 1. c, ligs. 22— 23. 



tabulata Ktz., V. IL, I. c, fig. A. 



Syn. d/f. with varieties have been found in 27 of the gatherings 

 from Bordo, Ostero, Stromo, Store Dimon and Sydero. Of the 

 varieties perhaps jxuva and »acuminata* occurred more frequently 

 than the others. They often covered the host plant as closely as 

 S. investiens. In a gathering from Kalbakfjord I found a variety which 

 in the nnniher of its striæ (9—10 in 0,01 mm. agreed with .S. a/f tabu- 

 lata, V. H., 1. c, fig. 9 A, men in its outlines with var. acuminata, fig. 14. 



100. S. commutata Grim., V. H. Syn. tab. XL., lig. 4. 

 Between Thorsvig and Kvalvig (Stromo). 



107. S. fulgens (Ktz.) W. Sin., V. H. Syn. tab. XLIII., ligs. 1—2. 



Skaalefjord (Ostero): Thorshavn Stromo); Tværaa Sydero. 

 Found frequently in the gathering from Thorshavn. 



S. fulgens (Ktz.) W. Sm. var. mediterranea Grim, V. II. I. c, fig. 3. 



Skaalefjord Ostero ; Trangisvaag Sydero. 

 Found fairly olien in the latter gathering. 



108. S. nitzschoides Grun. (— Thalassiothrix? nitzschoides Grun.), 

 V. H. Syn. tab. XLIII., ligs. 7—10. 



Kirkebo Stromo). One example only. 



109. S. undulata (Bailey) Greg., V. H. Syn. tab. XLII., lig. 2. 

 Rare. Skaalefjord (Ostero). 



MTZSCHIA Ilassall 1845, Cl. & (dun. året. I).. p. 07. 

 Panduriformes Grun., 1. c. p. 70. 



110. Nitzchia panduriformis Greg. var. minor Grun., V. H. Syn. 

 tal). LVIIL, lig. 4. 



Rather rare. Molen, Skaalefjord Ostero: Yaa^s Kjde (Sydero). 



