493 



compressa prefers the open sca-shores, where il olien forms ;i dense 

 covering on the rocks du ring high-tide, e. g., ;it Hojvig Fiesen«. It is 

 :ilso found in low-lying tide -pools of fresh water. Var. prolifera is n 

 form from sheltered localities and is found in the interior of fjords. 

 where, the water is only a little salt, and where it usuallv forms large 

 detached Qoating masses. Var. micrococca grows commonly on exposed 

 eoasts at a very li i^Ii level, where it is wetted h\ the spray only in 

 rough weather, and where il forms a pale-green helt, often associated 

 wiih var. minima and formå cornucopiæ of var. genuina. At Bosdalafos 

 at the wesl eoast of Vaago I have gathered var. micrococca al a lieight 

 of about 80 leet above sea-level. 



Almost all these varieties have heen observed in the months from 

 April to December, and fruiting in the same. They are common every- 

 where along the Færoese eoasts in localities suitable for their growth. 



165. E. clathrata (Roth) J. Ag. 



var. Rothiana Le Jolis, Uha clathrata (i Rothiana, Le Jolis, 

 Liste p. 50. 



var. Agardhiana Le Jolis, Liva clathrata « Agardhiana, Le Jolis, 

 Liste p. 49. 



The specimens referred lo var. Rothiana are fililbrm, and much 

 branched examples. The specimens referred to var. Agardhiana 

 have broader branches, and, the main branch being often dislinctly 

 broader, they then strongly resemble forms of what Ahlner calls 

 E. procera. 



As pointed out by Le Jolis, E. clathrata is distinguished by 

 ils decidedly genuine ramification, while, on the other band, E. inte- 

 stinalis var. compressa is proliferous, rather than branching, but 

 Le Jolis's exprcssion »rather« (plutol) indicales that it is often very 

 diflicult if not impossible to arrive at any definite conclusion re- 

 garding the specimens in hånd. 



In a gathering from Kalbakfjord, distinct Irabeculæ similar lo 

 those already mentioned under E. intestinalis var. comj)ressa and var. 

 prolifera were found in branches of a moderate thickncss. They 

 were distinctly visible through the walls of an uninjured plant 

 which bad been preserved in spirit. In this case again they were 

 nol true diaphragms, as a transversc seclion dislinctly showed, 

 bul only piates or trabeculæ stretching across a part of the lumen. 

 Some of the specimens referred lo this species were more or less 

 closely covered with short prolifications and somewhat resembled 

 Kutzing's figure in Tab. phyc, vol. 6, tab. 33; but from these very 

 proliferous examples Ihere was an easy transition lo specimens al- 

 most entirely without prolifications. I am of opinion that S i ni- 



