262 DN_THE DISPERSION Of MONTANE PLANTS
of Yorkshire, oi- of the range of Limestone hills that bounds the Slate hills of the lake country on the south, sti'etching from Kendal westward, past Milnthorpe and Arnside Knot, to the coast at Silverdale and Humphry Head ; all of which are similar in their litliology and botany to tract No. 2, and yield very few additional species.
Lid of Species.
1. ThaUctriim alpinum. Unknown in the Porphyry and Oolite. In the Slate on high damp crags of Helvellyn, Fairfield, and the Scawfell group of summits. In the Carboniferous tract confined to the super- agrarian basaltic crags of Teesdale.
2. Thalictruin minus, var. montannm. Unknown in the Porphyry and Oolite ; in the Slate, on a few superagrariau crags of the Skiddaw group only ; in the Carboniferous tract in one place only in Arkendale, on a limestone scar. Var. fleXHOsiim, in the Slate tract frequent amongst the large lakes ; in the Carboniferous tract scattered through the JMidagrarian zone in Teesdale, but not known in any of the other valleys ; unknowu among the Porphyry and Oolite.
3. Trollius europceus. Occurs more or less plentifully in all the four tracts, ascending in Teesdale to the Inferarctic zone.
4. Thlaspi alpestre. Unknown in the Porphyry and Oolite. Reported doiditfully or on doubtful authority from two places in the Slate district, and requiring confirmation before it can be accepted. In the Carbonife- rous tract, known in a dozen or more good stations, always about lead- mines, ranging in level from 100 to 750 yards.
5. Siibidaria aquatica. Unknown in the Porphyry, Oolite, and Car- boniferous tracts. In the Slate district in two of the large lakes.
6. Draha incaiia. Porphyry and Oolite unknown. Slate, reported from a single station on doubtful authority. Frequent in the Carbonife- rous tract on the high limestone cliffs in all the dales from the Wear to the Yore.
7. Arabis petraea. Unknown in the Porphyry, Oolite, and Carbonife- rous tracts. In the Slate district in two stations amongst the Scawfell group of summits.
8. Viola latea. Occurs in all the four tracts ; in the Oolite in two places only ; much more plentifully in the Carboniferous tract than in any of the other three.
9. Drosera amjUca. Unknown in the Porphyritic and Carboniferous tracts. Two stations each in the Slate and Oolite.
10. Silene acaidis. Unknown in the Porphyry, Oolite, and Carbonife- rous tracts. Several stations amongst the higher peaks of the Slate country.
11. Lychnis alpina. Unknown in the Porphyry, Oolite, and Carbonife- rous tracts. In the Slate district near the summit of one of the peaks of second-rate height, at about 2000 feet.
12. Arenaria verna. Universally distributed amongst the hills and dales of the Carboniferous tract, ascending to the Inferarctic zone. In the Slate known in two places only on precipices of the Inferarctic zone. Unknown among the Porphyry and Oolite.
13. Arenaria uliyinosa. In the Carboniferous tract on one hill in Teesdale at 5-600 yards. Unknowu in the other three districts.