i;{() L. IVOI.DKIU'I« HoSKNVINdK. 



I'll 111. Ulolhricaccæ. 

 lllothrix Külz. 



54. U. flacca (Dillw.) Tliur. 



K. H().sonviii{,'c (hSiCM p. iK};"); Wille (liMH) p. IS; Jonsson (l'.>()4) p. 04. 



Al the upper end of :i young Alaria sonic filamenls of a Ulothrix 

 were mel wilh which must be referred to Ihis .species. The swarm- 

 cell producing parts of the filaments were curved in the manner 

 cliaraclerislic of Ihe species and consisted of low cells undoubtedly 

 producing gametes'. The filaments were comparatively thin, the 

 IVrtile parls only reaching ^?> u in diameter. The cells oflen con- 

 lained only one pyrenoid, probably in connexion wilh the small 

 thickness of the filaments. 



Loc. Alonj» C.ape Hismarck l^eninsuln. 



55. U. scutata Jonsson. 



Jonsson (1904) p. 57. 



This species seems to be common within the region explored. 

 However, I am only sure of the determination of the specimens from 

 one locality, as I have seen only in these the basal part character- 

 istic of the species. Most of the specimens from the other localities 

 are dried. At the base the filaments were 5 — 7 /j. thick, and the 

 cells in the lower part of the filaments were frequently up to 4 

 times as long as broad. 



Loc. East Side of Koldewey Island. P\irther, uncertain as to the deter- 

 mination from dredf'inj' alon« Cape Bismarck I^eninsula, Danmarks Havn 

 and liaadskæret. 



56. U. consociata Wille. 



Wille (1901) p. 25; Jonsson (1904) p. 60. 



The North-East Greenland specimens agree with Wille's descrip- 

 tion; only they were rather thin. Young sterile plants were only 

 7 — 75 /i thick near the base, older filaments 105//, fertile filaments 

 12"5« thick. The filaments are often decumbent at the base and 

 form rhizoids there. Sometimes two filaments were found coalesced 

 near the base. The apical cell is rounded. — It was found growing 

 on Enieromorpha proliféra in the tidal region. 



Loc. Vestre Havnenæs, September. 



' lu stating (1893 p. 935—36) that I have found this species with zoospores in 

 West Greenland, I have not intended to saj»^ anything about the question whether 

 the swarm-cells were asexual zoospores or gametes. Probably they were gametes 

 (comp. Wille (1901) p. 21). 



