Acta Societatis pro Fauna et Flora Fennica, 49, N:o 7. 63 



Genus Sphaerozosma Corda. 



S. vertebratum (Bre b.) Ralf s; D e Bary, Unters. Conj. 

 pi. 4 f. 32 — 34. Our figures show the arrangement of the 

 pores in two series across the semicell, and the vertical 

 view, which not at all agrees with the figure of Ralfs 

 (Brit Desm. pi. 6 f. 1 f— g). — Long. 13, lat. 20, crass. 7, 

 isthm. 6>. [N:o 1255]. 



Hab. Esbo (S), leg. C. Cz. PI. 7 fig. 69-70. 



Genus Spondylosium Breb. 



S. pulchellum Arch., in Pritch., Infus. pi. 3 f. 10; 

 West, Brit. Frw. alg. p. 175 fig. 67 A — and var. bambu- 

 sinoides (Wittr.) Lund.; Wittr., Skand. Desmid. pi. 1 f. 

 12 page 25—26 [sub nom. = 5. bambusinoides Wittr.]; 

 Nordst., N.-Zeal. pi. 2 f. 11; Kaiser, Alg. Traunstein IV 

 page 145 fig. 19. 



Both the typical form and var. bambusinoides were 

 observed in Finland. The apices were always sligthly retuse. 

 The former is characterized by: the more open sinus with 

 regularly rounded basal angles and the length of the cells 

 = the breadth; the latter by: the closely linear sinus, which 

 at the end suddenly becomes widely dilated, causing an 

 angularity of the basal angles, and the length which exceeds 

 the breadth with 1 / i . These differences are, however, not 

 constant and obviously it is not always possible to make a 

 distinction between the two forms. Compare our figures 

 with the original ones and also the following measurements: 

 „f. typica": long. 10,6, lat. 8,6, isthm. 2,6 p (fig. 5) [N:o 1056]; 

 long. 9,2, lat. 9,2, isthm. 4 jli (fig. 6) [N:o 1204]; „var. bam- 

 businoides": long. 11,5 — 9,9 — 11,2—9,9, lat. 7,9—8,6 — 8,6 — 7,9, 

 isthm. 3,2 — 2,6—3,2 — 2,6, crass. 3,9 n (fig. 7 — 8) [N:o 1055]. 



Hab. In all parts of Finland. — The type PI. 6 fig. 

 5—6; the var. PI. 6 fig. 7—8. 



