147 



The plant forms in the sense here taken an intermediate link 

 between Eulithotliamnion and Lithophyllum, the above f. macro- 

 spora most nearly related to the former, and f. tenuissima as to 

 the structure forming transitions to the latter and occasionally not 

 easily separated from L. Lenormandi. Some of the specimens 

 that I in Contrib. 1 referred to L. Lenormandi really belong to 

 L. Stromfeltii. Owing to this confusion I lay no stress on my 

 notes as to the distribution of these species especially along the 

 coast of East-Finmarken, but refer only to the specimens that I 

 now possess. Later I met with rather numerous fertile specimens 

 of the last named, species, and, through the kindness of Prof. 

 Wittrock, I have examined authentic specimens of L. Lenormandi 

 in A resch oug's herbarium in the Riksmuseum at Stockholm. 



The named forms macrospora and tenuissima are certainly 

 not well defined, as transitions very often arc to be found, but 

 they are, on the other hand, in their most extreme forms rather 

 differing, so that I hold it most suitable to regard them as deno- 

 minated forms of the species. Nor are they -apparently the 

 only ones. 



The form macrospora is characterized by its more distinctly 

 zonated peripherical portion, having tendency to become orbicular 

 when freely developed on a plain substratum, and the margin 

 more regular. It is in general rather shining, sometimes even much, 

 the crust gets up to 400 fi in thickness, and the conceptacles of 

 sporangia are very large, 600 — 900 /j. in diameter or more, and 

 are more or less flattened, low, or nearly disc-shaped. The tetra- 

 sporic sporangia also are proportionally large, but very much va- 

 rying in shape as well as in size even within one and the same 

 conceptacle. However, they are frequently about 250— 600/;- long 

 and 100—200 fi broad. 



The form tenuissima sometimes is only 50 ;j- thick sometimes 

 attaining a thickness of 200 fi or even more, but specimens from 

 the more southern part of the coast seem in general to be thinner 

 than those from the northern. It has a more irregular outline, 

 being composed of smaller and more irregularly confluent crusts 

 than in f. macrospora. It is less shining, sometimes even rather. 



