Microplankton /rmu the Finnish Waters during the Monih of May 1912. 



II 



Melosira hyperborea (Grün.). 



(Fig. 0.) 



1880 — 85 Melosira nummuloides var? hyperborea Van Heurck, pl. 85, f. 3 — 4. 



1895 Östrup, p. 462. 



1896 b Schutt, p. 59. 



1897 b Gran, p. 4. 



A. Schmidt Atlas, pl. 182, f. 24. 



1897 M. nummuloides + M. Juergensii Vanhöffen. p. 265, pl. 3. f. 16 — 18. 



1900a Gran, p. 52, pl. 3, f. 11—15. 



1908 Gran, p. 13. 



1910 Meunier, p. 271, pl. 30, f. 16-21. 



J 



@ 



d. 



Fig. 9. Melosira hyperborea. 



a. (Jells without resting-spores. 



b. Cells with resting-spores. 



101 K j 



c. Resting-spores. d. Auxospore. 



Melosira hyperborea was either found in short chains, often containing resting- 

 spores, or as single resting-spores. At the same time many separate valves were found. 



N:o 5. 



