356 Dr James Stirton on Lichens. 



very restricted areas, whilst it can give only a very meagre 

 and imperfect representation of the lichen flora of New- 

 foundland, possesses considerable interest in another direc- 

 tion. 



While the main features of the collection are distinctly 

 of the North American type, there are several curious 

 tracings of other types, as the Norwegian, British, and, in 

 one instance, of what may be called the Mediterranean type. 



Again, as the two habitats are at or near the sea-level, 

 and the bulk of the species, as might have been expected, 

 is composed of plants commonly found in this zone, there 

 is a curious intrusion of individuals of other altitudinal 

 zones (especially European) — an intrusion to this extent 

 at least, that it cannot fairly be accounted for from the 

 geographical situation of the island as to latitude, and I 

 am not sure that the influence of known ocean currents 

 upon plant spread and growth will do much towards an 

 elucidation in this respect. 



For instance, Stereocaulon tomentosum, whose habitat is 

 mainly subalpiue in Europe, is here, as well as in North 

 America generally, on tlie littoral zone. 



2. Cladonia sylvatica^ var. alpestris, is another example 

 of the same kind, of a lichen found in the more northern 

 parts of Norway and Scotland. 



3. Alectoria cincinnata is only found in Scotland at 

 high levels, and, so far as my experience goes, only near 

 the summits of mountains of considerable elevation, and in 

 Norway near the White Sea, &c, 



4. Nephroma arcticum is only found in the northern 

 parts of Norway and in Arctic North America, or it may 

 be near the summits of the higher mountains further 

 south, as the White Mountains ; while here it is found in 

 abundance at the sea-level. 



Several instances of a similar nature might be mentioned, 

 as Umhilicaria arctica, whose range corresponds closely 

 to that of N. arcticum; but I desist from following out the 

 vein, and I shall merely mention one other instance of an 

 opposite character, viz., Rocella. 



Generally speaking, the range of species of this genus 

 is, for Europe, the Mediterranean ; the most northern limit 

 being the south coast of England, and it is difficult to 



