LICHENS. 133 
Tasmania, and Australia. It grows to a magni- 
ficent size on the summit of Table Mountain, 
Cape of Good Hope. In Europe it is found, 
besides our own country, in Spain, Greece, Turkey, 
and Germany. Its northern limit at Inverary, 
lat. 56° N., singularly coincides with the latitude 
of the most southern habitat at Cape Horn. 
Another species of the triad of tropical lichens 
found in Britain is the Sticta macrophylla. It oc- 
curs nowhere else in Europe but in the south- 
west of Ireland on shady rocks beside the Turk 
Cascade, near Killarney, and on Cromagloun 
mountain. Before its discovery in these places in 
1829, it had been known only as an inhabitant of 
the Mauritius, Madeira, and the Azores. It grows 
plentifully on rocks at Ribeiro Frio, Madeira, 
and fructifies abundantly there. It has also been 
found in South American forests on the bark of 
Cinchona trees. Its coriaceous thallus is imbricated, 
with flat blunt segments naked and smooth above, 
and clothed with brown fibres beneath. When 
fresh its colour is bright green, but it soon fades 
into a pale leathery brown, with a slight tinge of 
red on the edges of the segments. Its presence in 
Ireland, along with the remarkable Iberian flora 
which is found there, is a proof, as already re- 
marked, of the western extension of the European 
and African continents, and the existence of the 
