Contribution. I. 37 



The present plant is litoral, growing in rock-pools on 

 rather exposed shore Specimens collected in the later half 

 of July were sparingly tetrasporiferous. 



Distribution: Only found at Syltefjord, local, scarce. 



Gen. Dumontia (Lamour.) J. G. Ag. 



Spec. Alg. 2. p. 348, Lamour. Ess. p; 133; char. mut. 



Dumontia filiformis (Fl. Dan.) Grev. 

 Alg. Brit. p. 165; Ulva filiformis Fl. Dan. t. 1480. 



f. typica. 

 Descr. Dumontia filiformis J. G. Ag. Spec. Alg. 2, p. 349. 

 Fig. „ „ Harv. Phyc. Brit. t. 59 et 357 B. 



f. crispata Grev. 

 Alg. Brit, p. 165. 

 Descr. Dumontia filiformis /S crispata J. G. Ag. Spec. Alg. 2, p. 350. 

 Syn. Ulva filiformis Wg. Fl. Lapp. p. 508. 

 „ „ Sommerf. Suppl. p. 187. 



Gastridium filiforme Sommerf. in Act. Nidros. p. 51. 



The form crispata, as it appears at East-Finmarken, is 

 not distinctly marked. Here it is narrower and less twisted 

 than more southward, but on the other hand, it differs from 

 f. typici by its greater firmness and by the inner layer of 

 cells being larger. However, transitions are pretty common. 

 It seems to prefer freshwater-streams between tides. 



The present species is litoral, occurring most commonly 

 in rock-pools or other caves between tides, attached to stones, 

 shells or sometimes to lucaceae. It often grows gregarious 

 in rather considerable numbers, on open shore as well as in 

 sheltered places, and it even enters the inner end of the 

 greater bays. On much exposed places it becomes rather 

 reduced in size. The largest specimens I have seen had a 

 length of 35 cm., yet mostly smaller, sometimes only 5 cm. 

 It has been taken with tetrasporangia in the later half of 

 June, in July, and in the beginning of August (richly). I 



