Murchisori s Silurian System. 545 



can be better studied than to the north of Ludlow, where the for- 

 mation occupies a distinct range of hills rising to the height of four 

 or five hundred feet above the low country, and presenting escarpments 

 to the valley of Corvedale. In these hills are several calcareous zones, 

 separated by thick masses of sandstones, flagstone, and argillaceous 

 marl, the strata dipping slightly to the" north and south of east. 



" Some of the best flagstones of these hills are quarried at Bouldon. 

 The upper beds consist of marl, impure cornstone, and thin beds of 

 deep coloured red sandstone. Beneath these lie about twelve feet of 

 sandstone, which splits into flags. This stone is of a greenish colour, 

 and highly micaceous, and its surfaces are marked by those undulations 

 or ripple marks, so frequent in the sandstones of all ages, and which 

 are supposed to have resulted from the action of water during the 

 process of deposition. The flags are from three to eight inches thick, 

 and sometimes of great extent, and they are largely used for staircases, 

 doorways, wall tops, lintels, &c. ; a course of impure cornstone un- 

 derlies the flagstone. Similar flagstones, but generally of dull red 

 colours, are extracted at the southern end of the Brown Clee, and on the 

 south-western slopes of the Titterstone Clee. In the quarries of Sir 

 W. Raughton, Bart, at Downton Hall, flags are often quarried of the 

 great size of one hundred square feet. 



" A section of the strata between the slopes east of Downton Hall and 

 the valley of Corvedale is seen by reference to PI. 31. fig. 3., and the 

 structure of these beds is already sufficiently explained to render unne- 

 cessary the encumbering of these pages with similar details in other 

 places. The courses of concretionary limestone are as usual not con- 

 tinuous ; on the contrary, they expand and diminish, disappearing and 

 re-appearing in their horizontal range. 



" Similar exhibitions of concretionary limestone wrap round the sides 

 of the Clee Hills. 



" On the western face of the Titterstone Clee they rise to a great height, 

 both at and above Bitterly Court ; they surround the Brown Glee, and 

 are largely quarried at Abdon, Ditton, &c. It is not possible to include 

 these cornstones under one mineralogical description. In most places 

 they are of red and lightish green colours ; in others, however, they 

 are light brown, with veins of dark chocolate and green, a variety 

 of which in a highly crystalline form is extracted at Targrove, near 

 Downton Hall. At Ditton, white and green colours prevail; at Broms- 

 grove the mass is brown, with light grey patches ; while at interme- 

 diate places they consist of marl, limestone, and sandstone, irregularly 

 concreted, and have the aspect of a conglomerate. In the last mentioned 



