55 



there is nothing to add except some few localities, which may 

 be regarded as unimportant, the species certainly being com- 

 mon in West Greenland. 



The plants from East Greenland fully agree with the West 

 Greenlandic specimens. They were gathered in June and July. 

 Specimens with typical gametangia (Rosenv. Grl. Havalg. fig. 44 C) 

 were collected in June. 



Gr. or.: Ikerasak, Angmagsivik, Kangerdlugsuatsiak, Nualik. 



98. l. pseudoflacca Wille Studien p. 22, Ü. implexa K. Rosenv. 

 Grl. Havalg. p. 936, Deux. Mém. p. 115, pro parte. 



This species frequently occurs in the Greenlandic collections. 

 The specimens are somewhat varying, especially regarding the 

 length of the cell, and sometimes also as to the shape of the 

 basal cell. As a rule the basal cell is somewhat narrowed 

 towards the base, as described by Wille (I.e.), but in speci- 

 mens growing on Acrosiphonia 1 have occasionally met with 

 basal cells, the bases of which were somewhat expanded and 

 marked from the upper part of the cell by a slight narrowing. 

 As the specimens on Acrosiphonia in other respects agree 

 with this species, and the different shape of the basal cells 

 gradually runs into the normal shape, I have referred them to 

 U. pseudoflacca. 



The length of the cell is considerably varying; usually it 

 varies from Vé of the breadth to as much as the breadth, but 

 sometimes the cells are 1 V2 times longer than broad. The 

 length of the gametangia and zoosporangia varies in the same 

 w'ay as in the vegetative cells. The sporangia are usually of 

 the same shape as the sterile cells, but sometimes they are 

 somewhat thicker and of a more round shape. The zoosporangia 

 contain 4—8 zoospores of the typical shape. Most frequently both 

 zoosporangia and gametangia occur in the same filament. The 

 thickness of the filaments varies from 9 — 23//. In other respects 

 the structure of the cell of the Greenlandic specimens agrees 



