South-western Coal District of England. 227 



oolite, sweeping westwards^ closes over the edges of the limestone strata, and 

 abuts against the southern flank of the ridge of old red sandstone, from East 

 Cranmore to Downside, north of Shepton Mallet ; but further westwards the 

 lias invests the inclined strata. The southern band of limestone is thus every 

 where concealed in this tract, except in one small point called Waterlip, north 

 of Doulting, where it emerges from under lias and is discovered in close con- 

 tact with the old red sandstone. [PI. XXXII. fig. 1. A.] At the limestone 

 crag of Windsor-hill, situated 2 miles to the north-west of Shepton Mallet, the 

 limestone is again exposed to view, dipping to the south at an angle of 45°, 

 and from thence it passes round the southern and western flanks of Masberry 

 Castle. From Masberry Castle it extends southwards over a low tract nearly 

 2 miles broad ; but further to the south the calcareous border presents so many 

 irregularities, that it would be tedious to follow it in a verbal description, and 

 we must beg to refer for its outline to the map. 



These irregularities are occasioned by three ridges of mountain limestone, 

 which here lie to the south of the principal chain, and parallel to it and to one 

 another. The valleys between them are occupied by the dolomitic conglome- 

 rate, while the higher table-land of lias, extending from Shepton Mallet, re- 

 poses in terraces upon their eastern extremities. 



These ridges are, 1 . Lyall-hill [see the Map and PI. XXXII. fig. 2.] on the 

 north of Binder : 2. Dulcot-hifl [see Map, Plate and figure last quoted^, rising 

 with a craggy mountainous outline, to the east of the village of the same name; 

 and broken into two parts in its centre. Its strata are inclined at an angle of 

 30*^ to the south, and it is covered by the terraces of lias near a place called 

 Dungeon. [PI. XXXII. fig. 1. B.] 3. Knowl-hiH and Worminster-hill, close to 

 the villages of that name. They are two distinct eminences, but being placed 

 on the same line of bearing may be considered as fragments of one ridge. 

 [PI. XXXII. fig. 1. B.] Where these ridges inosculate with the principal 

 chain, near the village of Cross Combe [same Plate and figure], a most pictu- 

 resque defile extends northwards, the top of which, lofty as it appears from 

 below, is only on the same level with the lias plain extending from Shepton 

 Mallet. The precipices of mountain limestone, which skirt it, are fringed 

 with luxuriant woods. Near its mouth, on the east side, a large rock of con- 

 glomerate adheres to the summit of the limestone cliffs. 



The northern portion of the calcareous zone, which surrounds the eastern 

 nucleus of old red sandstone, may be traced eastwards in a straight line from 

 the western extremity of Masberry Castle, near Slab House, to Mells. This 

 zone, from being two miles broad near to Masberry Castle, is reduced to the 

 breadth of half a mile at its eastern extremity. Its northern boundary coin- 



