2 M. FOSLIE, (Sch\ve<l. Südijolar-Evp. 



gion, whereas Lithophyllnm œquabile, which seems to be most largely dispersed 

 within the western part of the same region has also been found on the coast of 

 South Georgia. The other species mentioned have their greatest frequenc}- in the 

 subantarctic region. Thus Lithothaninion antarcticum is widely dispersed within 

 the colder Southern Hemisphere; Litltotliauinion inagellanicum is known only from 

 the western part of these areas and particularly occurs on the coasts of Fuegia and 

 the Falkland Islands; Lithophyllum decipiens is wiéely dispersed, chiefly to the north, 

 both along the Atlantic coast and the Pacific coast of America. It is, however, 

 possible that this species, as it has hitherto been circumscribed, should in fact in- 

 clude two or three species. Cp. below under the particular description of the species. 

 Of characteristic western subantarctic species, Lithopliyllitm discoideiim seems 

 to be the most frequent one. It corresponds to the northern Lithophyllnut in- 

 crustaus, which occurs in great numbers particularly from the southern part of 

 Britain to the north coast of Africa. It is also closely connected with the West 

 Indian Lithoph. intermedium, which is, however, a species as yet but little known. 

 Of other characteristic species must be mentioned Lithotli. riigosnm, which occurs 

 on the coasts of Patagonia and of Fuegia, where, no doubt, it is regularly dispersed. 

 It seems to correspond to arctic Lithotli. glaciale, but is much smaller. From the 

 same area also another species is known, which perhaps has its next of kin in the 

 north, namely Lithotli. heterocladum. In habit it resembles Lithotli. calcareinn, 

 fairly much dispersed in warmer boreal areas, but in other respects it also ap- 

 proaches Lithotli. rugosmn. 



In a phytogeographical point of view the Falkland Islands are included under 

 the Fuegia district with subantarctic vegetation. As to the calcareous algœ there 

 is an intimate correspondence between the different parts of this district. Simulta- 

 neously, however, particularly a species occurring at the Falkland Islands, Litho- 

 phyllum falklandicum mentioned below, is so closely connected with South-African 

 Lithophyllum Marlothii that at first I considered the former as a variety of the 

 latter. There is every probabihty that one of these species has risen from the other. 

 At the Falkland Islands is found also another species, Lithotli. variabile, which is 

 nearly connected with a South-African calcareous alga, Lithotli. synanablastnm. 



On the other hand, it is at present impossible to decide if as far as the said 

 algœ are concerned, there is really any close connection between the western and 

 eastern parts of the subantarctic region. A species, Lithoth. antarcticum mentioned 

 above, is certainly dispersed in both parts of this region. It is, however, a small 

 epiphytic calcareous alga which attaches itself to other alga;, and will, therefore, 

 like e. g. Melobesia farinosa, be more easily spread over larger areas than calca- 

 reous algje which are attached to hard objects or developed freely on the bottom. 

 Of the last mentioned ones none is as yet known that is dispersed in both parts of 



