On the Marine Algæ from North-East Greenland. 127 



one to several hundreds (fig. 8), while Cb. tortuosa has ca. 20 nuclei 

 in each cell (K. Rosenvinge 1893 p. 917). 



The species seems to attain a greater thickness in high latitudes 

 than farther south. According to Kjellman (1877 p. 56) it also reaches 

 at Spitzbergen a diameter of ca. 1 mm., while its maximum diameter 

 is otherwise stated to be 800/^ on the West coast of Sweden (Are- 

 schoug (1850) p. 202), 700, a in the North Sea (Hauck 1885 p. 438) 

 and 500 fx on the New England coast (Farlow 1881 p. 46). 



In one gathering only it was found attached to a stone. These 

 filaments had a diameter of at least 400 /7. 



Loc. East Side of Koldewey Island; Danmarks Havn. 



Farn. Cliœtophoraceœ. 

 Arthi'ocliæte K. Rosenv. 



49. A. penetrans K. Rosenv. 



K. Rosenvinge (1898 I) p. 111. 



This peculiar epi- and endophytic alga, which seems not to 

 have been found by others since it was described in 1898, is rather 

 frequently met with in older fronds of Turnerella Pennyi, in parti- 

 cular on discoloured spots. The plants fully agree with those from 

 Scoresby Sound. The epiphytic crusts are in great measure poly- 

 stromatic. Numerous sporangia, mostly empty, were found in plants 

 collected in September. 



Loc. East Side of K^oldewej' Island; Danmarks Havn. 



50. A. phæophila sp. n. 



Thallus endophyticus e filis irregulariter ramosis inter fila thalli 

 Symphyocarpi strangulantis repentibus compositus. Fila primaria 

 horizontalia ramosa, ramos breves verticales etiam emittentia; fila 

 nonnunquam in massam pseudoparenchymaticam confluentia. Cel- 

 lulæ subcylindricæ aut magis rotundatæ ad subglobosæ, longitudine 

 diametro æquantes vel ad duplo longiores, lat. 9 — 15/^, chromato- 

 phorum pyrenoide uno vel duobus instructum continentes. Pili ar- 

 ticulât! laterales vel terminales filis repentibus et erectis impositi, 

 inferne 55 — Q5n crassi. Sporangia obovata ad subglobosa in filis 

 repentibus vel erectis lateralia aut terminalia, nonnunquam plura 

 dense aggregata, apice dehiscentia, long. 14—25/^, lat. 10 — 21 /i. 



This new species has only been met with in small quantity in 

 a few dried crusts of Symphyocarpiis strangulans growing on a Litho- 

 thamnion-crnst. The filaments creep irregularly between the cells of 

 the host, in particular horizontally, in accordance with the small 

 thickness of the host. They are often much branched, particularly 

 in a horizontal direction, but short erect filaments are also given 



