24 
part of the county, and the parallel ranges of hills between Teesdale, 
Swaledale, Wensleydale, and Nidderdale, which lies above an elevation 
of about three hundred yards, and below the limits of possible cultivation. 
Its surface consists principally of broad bleak moorlands, sparingly inter- 
spersed with cultivated land, and consequently there is not nearly so 
much variety in situation as in the zone below, and the number of species 
which make up its flora is comparatively small. The bulk of its vegeta- 
tion is composed of species which would naturally be equally plentiful in 
the lower zone, but which have there been considerably diminished in 
quantity by drainage, and the operations of agriculture : as Calluna vulga- 
ris, Erica Tetralix and cinerea, Nardus stricta, Juncus squarrosus, Scirpus 
csespitosus. The species which make up the colonist class of citizenship, 
many of which are plentiful in the lower zone, are here comparatively 
rare, whilst the aliens are almost altogether wanting. Some of the species 
which belong to the two boreal types of distribution (i. e. the Highland 
and Scottish) appear in the riding to be peculiar to this zone, but they 
are mostly of very limited diffusion. Of this class Saxifraga Hirculus, 
Hieracium iricum and croeatum, Meum athamanticum, Arbutus Uva ursi, 
Allosorus crispus, Equisetum umbrosum and variegatum, are examples. 
Other species, as Draba incana, Rubus Chamsemorus, Saxifraga aizoides 
and stellaris, Bartsia alpina, Gentiana verna, and Carex capillaris, are 
common to this and the upper zone. 
The upper or inferarctic zone comprises those mountain summits, about 
twenty in number, near the western boundary of the county, which rise 
above the limits of possible cultivation. Marked upon the map, the por- 
tions of surface which it embraces appear to consist of two groups : one 
of them a horse-shoe shaped tract encircling the head of Swaledale, 
with several minor circular patches in its vicinity : the other a single 
oblong streak between Lunedale and Teesdale. The flora of this zone is 
made up of only a very small number of species, and is best characterised 
by the absence of a large class of plants which are common in both the 
zones of the Agrarian region, including all the more conspicuous trees 
and shrubs, and the weeds which attend upon cultivation. A few, however, 
of the species belonging to the Highland type of distribution, appear (in 
the riding) to be peculiar to it. Amongst these are Myosotis alpestris, 
(the most thoroughly boreal species which has been found in Yorkshire,) 
