258 The Scottish Naturalist. 



in this country, at least, it has hitherto been identified. Of this 

 moss I have specimens from near the summit of Ben Macdhui, 

 gathered in 1868 by the late Mr. George E. Hunt, from near the 

 summit of Ben Nevis by myself in 1866, and from the Breadalbane 

 mountains by Mr. James M 'Andrew, in July, 1885. 



This moss differs from all states of D. arcticum that I have seen 

 in respect of the stems, which are much more laxly tufted and 

 longer, varying from 2 to 4 inches in length. The leaves are 

 more distantly placed on the stem, are broader and longer, more 

 longly acuminate, straight, and somewhat spreading when dry, as 

 well as spirally twisted in the upper half. The main distinction, 

 however, between the two is in the areolation, which in the moss 

 under consideration resembles much that of D. scoparium, but has 

 none of the lateral connecting pores. This areolation is narrowly 

 cylindrical throughout, and is in parallel rows, but towards the 

 base is somewhat sinuous, and has several (2-4) minute oil globules 

 disposed pretty constantly, and in linear series, in each cell. In 

 D. arcticum there is only one globule or nucleus seen near one of 

 the angles. The dimensions of these cells vary thus, ( # o45--o9) x 

 oo 55"' oo 9) mm - 1 while in D. arcticum they vary, (*o45-'o75) x 

 (*oo9-'oi5) mm., z.e. } their breadth is about twice as much in 

 the latter, whose apical cells become also, as a rule, much shorter 

 and broader. In the moss in question the alar cells are 

 large, and of a deep red colour, while in D. arcticum they are 

 orange or reddish-orange. The nerve is narrow, , o5-*o8 mm. in 

 breadth, and becomes lost in the upper fifth. The back of nerve 

 and margin are entire throughout, and smooth, not papillose. The 

 margin is involute, and often nearly overlaps in the middle third, 

 while the apex is very fine, and tapering. There is no tomentum 

 on the stem. I propose to distinguish this moss by the name 

 D % hypsclum. 



BEITISH MAKINE ALGH. 



By E. M. Holmes, F.L.S., RR.B.S.E. 



[Note. — Two plates of figures to illustrate this paper are issued with this 

 Number of the Scottish Naturalist.] 



ON comparing the Marine Flora of the British Islands with 

 that of the neighbouring coasts of Norway and of France, 

 one is struck by the fact that a large number of species occurring 

 on these shores have not yet been detected in Great Britain. A 



