MicroplanJcton from the Finnish Waters during the Muxlh of May 1912. 



L3 



1905 Jörgensen, p. 105, pi. 7, f. 22. 



mos Gran, p. 124. 



1910 Stauropsis Vanhöffenii Meunier, p. 322, pi. 33, f. 46. 



Fig. 10. Navicula Granit. 

 950 

 1 



Fig. 11. Navicula Vanhöffenii. 



1150 



1 



Most of the Navicula-chains belonged to this species. It occurred in single cells 

 or in chains consisting of 2—4 cells. One chain having the breadth of 45 a has been 

 drawn; it was found at station F 50 at the depth of 10 mètres. 



Nitzschia longissima (Breb.) Ralfs. 



(Fig. 12.) 



1880—85 Van Heurck Synopsis, p. 185, pi. 70. f. 1—4. 



1899 Karsten, p. 114, f. 178. 



1908 Gran, p. 131. 



1910 Meunier, p. 337, pi. 34, f. 41—46, 65. 



This species occurred sparsely at two of the stations, viz: F '23 and F 41. While 

 it was found in every sample from the surface to the depth of 60 mètres at station 



Fig. 12. Nitzschia longissima. 



1000 



1 



F 23, it was only observed in the sample from the surface at station F 4 1 . It is noted 

 as littoral by Gran; yet according to Van Heurck it is no real form of the brackish 

 water. The length of the cells was about 100 <<. 



N:o 5. 



