534 G. T. HARRIS ON MICROSCOPICAL METHODS 



easily transported by strong winds or contact with moving 

 objects. The leaves are easily detached and often bear at their 

 tips tufts of radicles which give rise to new plants. 



Fissidens exilis. 



One of the smallest species of the Fissidentaceae and readily 

 known by its non-bordered leaves. 



Fissidens viridulus. 



Known from the preceding by its leaves having a narrow 

 border to them, but the variety Lylei has the border wanting 

 except on the sheathing laminae. 



Fissidens algarvicus. 



I am able to include a specimen of this new British moss through 

 the kindness of Mr. G. B. Savery, its discoverer in England. 

 It comes near Fissidens pusillus, and so far has only been found 

 in two localities, Silverton in Devonshire, where Mr. Savery first 

 discovered it, and near Cheltenham. It is characterised by its 

 narrow acute leaves with rather strong and narrow border. 



Fissidens bryoides. 



An extremely common and variable species, the forma in- 

 constans was originally a separate species, but is now generally 

 considered to be merely a " form " of F. bryoides. As will be 

 seen from the two slides, the difference is considerable in general 

 appearance, and I have found the form inconstans to be little 

 subject to variation from widely different localities. 



Rhacomitrium lanuginosum. 



This is the largest British species of the Grimmiaceae, and 

 often covers immense tracts of mountain moorland with great 

 masses. The hyaline and papillose serrated leaves are very 

 beautiful. 



Hedwigia ciliata. 



Another inhabitant of dry, rocky localities, with, as is usually 

 the case with such mosses, hyaline apices to its leaves. The 



