A. CLEVE-EULER, DIAT. FLORA OF FINLAND. 63 



Distr. {7nar.): Arctic Sea, Atlantic etc. Ubiquist (»die 

 verbreitetste aller marinen Diatomeen», Grunow in Franz 

 Jos. L. D., p. 41). 



Paralia sulcata (Eiib.) var. siberica Grun. — Franz Jos. 

 L. D.. p. 42. V. H. Syn. Tab. 91, f. 22. 



Foss. : Kk. Knjäsha, rare. 



Distr. {77iar.): East Arctic Sea. 



Paralia sulcata (Ehb.) var. minima 0str. — Mar. D. 03t- 

 Gronl. Tab. 8, f. 91. 



Foss.: Kk. Knjäsha, rare. 



Distr. (mar.): East Greenland. 



Perhaps this variety is nothing but the smallest indivi- 

 duals of Paralia sulcata f. genuina, showing valvar impres- 

 sions as a consequence of the elongation of the cellules in 

 pervalvar direction. 



Melosira Ag. 



Melosira islandica 0. M. subsp. helvetica 0. M. — Jahrb. 

 f. wiss. Botanik, 43 (1906), p. 67, Tab. 1, f. 7—9. A. Cleve- 

 Euler, Pleom. Melosira, p. 124 etc., f. 1—22. 



Ladoga. Foss.: Ab. Hindersmossen; Xyl. Kyrkslätt; Sat. 

 Panelia. Frequent in fossil lacustrine deposits from the An- 

 cylus-eipoch. 



Distr. {fresh iv.): Plankton of many large lakes in Fenno- 

 scandia and Central Europe. 



This form is perhaps identical with the -»^lelosira distans» 

 of Levander, quoted limnetic in several Finnish lakes (Acta 

 Soc. Fauna & Flora Fennica, 9 n:o 2, 1900). 



Then Melosira helvetica is, as I have previously shown, 

 identical with »Melosira {distans var.?) laevissima» Grun, in 

 V. H. Syn. Tab. 86, f. 24, while the typical M. distans is 

 doubtful as a planktonform. 



Melosira italica Kütz. f. laevis (Grun.). — Melosira 

 {crenulata var.?) laevis Grun. V. H. S}^. Tab. 88, f. 19. 

 Foss.: Ab. Hindersmossen, Nyl. Kyrkslätt. 



Melosira italica Kütz. subsp. subarctica 0. M. — Jahrb. 

 f. wiss. Botanik, 43 (1906) p. 70, Tab. 2, f. 7—11. 



Ladoga. Foss.: Ab. Hindersmossen; Xyl. Kj^rkslätt; Sat. 

 Panelia; frequent in early postglacial, lacustrine deposits. 



