250 POLYSTICHUM LONCITITIS. 
also branched. The fructification is borne by the lowest 
upper branch of each side-vein, forming a row of masses 
pretty close to, and on each side of, the mid-vein. The 
lobe of the leaflet has a small raid-vein of its own, and 
masses of fructification are on each side of it. The 
fructification rarely occurs except upon the upper leaflets 
of the fronds. The cover (indusium) of each mass is 
circular, fixed by the centre, notched on one side, and 
separating all round as the sori, which are light brown, 
increase in size. 
This species is rare, and found only in mountainous 
districts in the north of the British Islands. Its favourite 
haunts are the clefts of rocks near the mountain tops. 
In England it has been found about the upper part 
of the Tees ; near Settle, in Yorkshire ; on Swarth 
Fell, near Ulleswater, and other parts of Cumberland. 
In Wales, at Clogwyn-y-Garnedh, Snowdon ; and on 
Glyder, near Llanberris. 
In Scotland, very common in the Highland valleys 
and exposed mountain sides. On the Bredalbane 
Mountains, Perthshire, at an elevation of about 3,000 
feet ; Craig Chailleach, Perthshire ; Clova Mountains, 
and Glen Isla, Forfarshire ; on Ben Lawers, and Falcon 
Glints, near Chaldron Spout, Teesdale ; Aberdeensbire, 
Moray, and Ross-shire; base of Benmore, Sutherland; 
on Ben Lomond ; and in Glen Phee. 
In Ireland, on Bandon Mountains; in a glen east 
of Lough Eske, Donegal ; and on Glenade Mountain, 
Lei trim. 
Polystichum lonchitis was not known as a British 
