221 



The species forms crusts on slones and gravel, in depths from 5 to 24,5 meters. 

 In one case it was found growing on a dead specimen of Lithothamnion calcareum. 

 It has been found with sporangial conceptacles and cystocarpic conceptacles in 

 May and September. 



Localities. Sk: Off Hirslials, 13 met. (F. Borgesen). — Lf: ZY, Nissum Bredning, 5 met. (deter- 

 mination uncertain). — Ku: Herthas Flak, 20 — 23 met.; FF" and TR, Trindelen, 23,5 and 15 met. — 

 Ke: IP and IL, Fladen, 20,5 24,5 met; IK, Lille Middelgrund, 17 — 19 met. — Sb : GP near the light- 

 buoy at Halskov Kcv (no. 3171, see above); Strandby reef, W. side of Langeland (?). — Sill : VC, Vene- 

 grund, 4 — 5,5 met. 



4. Lithothamnion glaciale Kjellm. 



F. R. Kjellman, Norra Ish. algtl. p. 123 (93) tab. 2 and 3. Foslie, Norw. Forms p. 13; Remarks p. 26. 

 Mme P. Lemoine, Struct, p. 92. 



Nearly all the rather numerous Danish specimens referred to this species have 

 been determined by Foslik, who received them from me at ditTerent times and ac- 

 cordingly gave them ditTerent names. In 1895 he described and figured Norwegian 

 specimens, corresponding exactly to those mentioned here as var. Granii, under the 

 name of L. flabellatum f. Granii. Later on this variety was referred to L. glaciale, 

 an opinion which has only been expressed in Rev. Surv. (1900, p. 11, where after the 

 name L. Granii, which is here a nomen nudum, is added: "(L. glaciale f. ?)"). As late as 

 in 1905 Foslie referred specimens of these algae to L. glaciale, partly to f. Granii, 

 partly to other forms. But in the same year (Remarks p. 59, ') Foslie established 

 L. Granii as a distinct species. That he has been uncertain at the last as to the 

 limitation of the species can be concluded from the fact that the same species, on 

 p. 10 of the same paper, is mentioned as L. glaciale f. Granii. It is easy to under- 

 stand that it has been difficult to come to a decision as to the delimitation of species 

 when considering that Foslie (Remarks p. 28) "found it almost impossible to draw 

 any line between L. Granii, admitted below, and L. glaciale''. L. c. p. 59 is said, as 

 to the relation between L. Granii and L. tophiforme f. divergens, that there are many 

 specimens "which are quite like each other in almost every respect, but that the 

 specimens of one species show a somewhat greater tendency in one direction and 

 the other in a ditTerent one". It is however not to be seen in the named paper on 

 which characters the difference between the two species really rests, save that L. 

 Granii has thinner, usually more ramified branches. Some Danish specimens for- 

 merly determined as L. glaciale, in part as f. colliculosa, are now (Remarks p. 34) 

 referred to L. colliculosum which is here regarded as a separate species, while he 

 had formerly considered it a form of L. glaciale; a description of it is given, but 

 he does not emphasize how it differs from L. glaciale. As I cannot see any distinct 

 difference between these specimens and some of those referred by Foslie to L. Granii 

 I prefer to adhere to Foslie's somewhat older opinion in regarding L. colliculosum 

 and L. Granii as varieties of L. glaciale. 



' Foslie's "Remarks" appeard however only in 1906. 



