36 M. F0SL1E. [1905 



The form pusilla seems most likely to have to be regarded as 

 a stunted form of the species, corresponding to L. Gr.anii f. re- 

 clucta. The branches, however, are often comparatively shorter, 

 thinner and more coalescing than in the typical form. Sometimes 

 it is hardly distinguishable from young specimens of L. Granii. 



As to conceptacles, 'the species comes near to L. Granii. 

 Those of sporangia partly are gradually overgrown, partty and 

 more frequently they are not so. 



L. colliculosum occurs in the lower part of the litoral region, 

 sometimes in pools, but particularly in the upper part of the sub- 

 litoral region and descends to a depth of about 10 fathoms. The 

 alga occurs both in exposed places and in sheltered ones where the 

 tides run rather strongly. It is fructiferous in January — March, 

 and June— September. 



Area: Norway: Skorpen in Tromso amt, f. pusilla (I), the 

 Trondhjemsfjord, f. typica, f. pusilla (!), Haugesund f. typica (No- 

 rum!,!), Kragero, {.typical Drobak in the Christianiafjord, f. pusilla 

 (Gran!,!); Sweden: Fiskebackskil, young f. typica (Areschoug!), 

 Vadero Storo, young f typica (Lagerheim !), off Gullmar fjord, 

 f. typica, f. pusilla (Arwidsson!) ; Denmark: Limfjord, young 

 f. typica (Rosenvinge!); Scotland: Berwick, Cumbrae, young f. 

 typica (Batters!). 1 ) 



8. Lithothamnion intermedium Kjellm. 



N. Ish. Algfl. (1883), p. 127; Stromf. Algveg. Isl. (1886), p. 19; Fosl. Contrib. 

 I (1891), p. 7, partim; Lithothamnion fruticulosum f. intermedia Fosl. Norw. Lithoth. 

 (1895), p. 18; (non Kiitz.); L. Ungeri Fosl. Rev. Syst. Surv. Melob. (1900), p. 11, 

 partim; De Toni, Syll. Alg. IV (1905) p. 1734, partim. 



f. subclistans Fosl. mscr. 



Lithothamnion intermedium Kjellm. 1. c. t. 4, fig. 2 ! 



The basal crust sending forth simple or subsimple, subdistant 

 branches. 



*) The specimens from the Atlantic coast of North America which in Norw. 

 Lithoth. p. 75 were referred to this species I now consider as representing 

 young forms of L. glaciale, although they are in part scarcely distinguish- 

 able from young specimens of L. colliculosum. 



