Mr. Winch on the Distribution of indigenous Plants. 53 



of remark, that in this formation, no stratum of Limestone intervenes 

 between its Shales and Sandstones, no well authenticated marine 

 exuviae occur in its beds, nor do any overlying masses of Basalt occu- 

 py the surface, that species of rock being confined to the Dykes which 

 traverse its measures. 



Nearly the whole of this division of the country being of inconsider- 

 able elevation, and chiefly in a state of cultivation, is of course unpro- 

 pitious to the production of scarce plants ; still several of the less 

 common Ferns flourish in the recesses of the obscure and damp denes, 

 while Convallaria majalis, Pyrola media, Pyrola minor, Trollius europceus. 

 Allium arenarium. Campanula latifolia, Vicia sylvatica, Andromeda poli- 

 folia, and Drosera anglica, are found in the more open of its woods, its 

 coppices, and bogs, and a greater variety of native Roses adorn the 

 hedges, than are to be met with in any other part of the island. 



Detached portions of the Magnesian Limestone may be noticed at 

 Whitley, CuUercoats, and on Tynemouth Castle rock, but its regular 

 course commences on the coast near South Shields, crossing the river 

 Wear near Hilton Castle, the South turnpike road, at Ferry Hill, and 

 the Tees in the vicinity of Pierce Bridge; and in its range southward 

 is bounded on one side by the upper beds of the New Red Sand Stone, 

 and on the other, by the Coal and Encrinal Limestone strata. No 

 other description of rock intervening between its strata, though resting 

 upon two interesting members of the New Red Sandstone, of which 

 formation it should, in fact, be considered a part, and generally at no 

 great depth below the soil, its influence on the vegetable productions of 

 the tract are very obvious, for the plants pecuHar to calcareous districts 

 now become common, if not predominant ; and here for the first time, 

 Tamus communis, a plant of the South of Europe, and North of Africa, 

 makes its appearance in woods and thickets. Cypripedium Calceolus, 

 Ophrys apifera, Oplirys muscifera, Epipactis ensifolia. Orchis ustulata, and 

 many more of this interesting order adorn the denes, the meadows, and pas- 

 tures. Warden Law,* four miles west of Seaham, the highest Magnesian 



* Tliis hill is not Limestone at its summit, being capped by a very thick bed of Dilu- 

 vium, among which may be noticed water-worn fragments, not only of rocks belonging the 



