336 Mr. IIooKru's Observalions on Andrcm. 



been observed only by Mr. Borrer and myself upon tlie rocky 

 summit of Ben Nevis, a mountain scarcely to be equalled by 

 any other in Great Britain for the richness and rarity of its ve- 

 getable productions, particularly in the order of Miisci, and 

 which, from its vast extent, must be as yet but partially explored 

 by the Cryptogamic botanist. 



A. nivalis produces capsules in the month of July, but spa- 

 ringly, although the male fructification is to be found in plenty at 

 that season, and is easily distinguishable from the rest of the 

 plant by its paler colour Barren specimens, and especially the 

 variety jS, have very much the appearance at first sight, both in 

 the mode of growth and colour, of Mr Dickson's Jungermannia 

 adunca, but the slightest examination of the leaves with a com- 

 mon pocket lens will be sufficient at once to distinguish them. 

 Its nearest affinity is with the preceding species, from which it 

 may always be known by its far greater size and different colour, 

 by the similarity of the perichsetial leaves to the cauline ones, 

 and by these latter, which are much broader and by no means 

 subulate, so that the nerve is furnished on each side with a 

 considerable portion of the leaf tu the very apex, whereas in 

 A. Rothii it occupies towards the apex almost the whole breadth 

 of the leaf. The pedicellus too has a peculiarity that I have not 

 observed in any other species, in its base where the barren pis- 

 tilla are situated being incrassated into a sort of bulb. 



Explanation of Tab. XXXI. 

 Fig. 1. Andr.'ea alpina. 



a. portion of a branch, magnified 6 



h. leaf 5 



c. exterior 



