786 



Of the remainding 20 species, 6 are the above mentioned new species 

 and 3 are forms only determined as to the genus, and of which we 

 know nothing concerning their eventual occurrence on the coasts of 

 Scotland. It is, however, most probable, that at any rate some of 

 them will be found to grow there. Of the remainding 11 species, 

 5 belong to Acrosiphonia and Spongomorpha which should be left out 

 of consideration because of the uncertain classification of these 

 genera; most Hkely they will all be found, however, on the coasts 

 of the British Isles, with the exception perhaps of A. hystrix, a 

 northern species uncommon even in the Færoes and not found 

 there either in its typical form. We thus have a remainder of 6 spe- 

 cies: Rhodophyllis dichotoma, Halosaccion ramentaceum, Ptilota pecti- 

 nata, Rhodochorion peniciUi forme, Lithothamnion læve and Alaria Pylaii. 



These 6 species are essentially typical to northern regions; they 

 all belong to the coldest portion of the subarctic group and thus 

 are species having their greatest distribution in the Polar Sea 

 proper. Whether any of these species may be found at the British 

 Isles is certainly very doubtful, but even if they do not grow there 

 and some few of the above mentioned Færoese algæ, which have 

 not yet been found in Scotland, should really be wanting there, 

 it is, however, but a very small number of species found at the 

 Færoes which are not found in Scotland or at any rate may not 

 be supposed to grow there. 



Any further examination dealing with the great number of 

 species found in Scotland and the surrounding isles, but not at 

 the Færoes, has but little interest liere. It is a matter of course, 

 that a much greater number of species must be found in a terri- 

 tory of such an extent, than at the Færoes, and it is likewise 

 evident that a great number of more southern forms will appear 

 there on account of the more southern situation of Scotland. Of 

 the species (about 250) found there, but not at the Færoes, more 

 than one half have hitherto only been found in the southern 

 part of Scotland, comprising the east coast about the Firth of 

 Forth (Fife, Haddington, Berwick) and the west coast reckoned from 

 Argyle to the English boundary; of red and brown algæ there are 

 no less than 68 species (see Borgesen and Jonsson 12, p. XXI, 

 group E 3). Of the remainding species (as to the red and brown 

 algæ compare the group E 2, in the above -mentioned paper (12) 

 p. XIX and XX) we may be sure that a great many do not grow 

 so far north as the Shetland Isles. 



