LIMESTONE ^ CALCAREOUS SANDSTONE. 73 



In some places, however, we find a bed of blue and grey lime- 

 stone under the oolite, not immediately succeeding it, but with some 

 other strata interposed. This is the case at Filey Bridge, where the 

 rocks ( e) form the series under the oolite; which, as was observed, 

 is there wanting. The uppermost beds, several feet in thickness, 

 consist of calcareous sandstone; and beneath these is a bed of blue 

 limestone, clouded with grey; bearing a strong resemblance to what 

 is found in the Malton quarry mentioned above. It has not the 

 oolitic structure; but it presents the same clouded mixture of blue 

 and yellowish grey stone, and the latter, as at Malton, is more sandy 

 than the blue part of the bed. It may be supposed, indeed, that at 

 Filey Bridge, the beds immediately under the oolite have disappeared 

 along with it, and that this bed has no con-espondence Avith those 

 already described, but belongs to another part of the series. On this 

 subject we remark, that whatever beds may have shared the fate of 

 the oolite at Filey, there appears to be no other bed in the series to 

 which this clouded stratum bears any analogy, except that with which 

 we are classing it. 



Among the varieties of this member of the series may be placed 

 the limestone of Hildenley, between Malton and Castle Howard. 

 It differs, however, from all the limestones now described, in the 

 whiteness and uniformity of its colour, which is that of light coloured 

 marl; and, being at the same time compact and uniform in its com- 

 position, it is excellently adapted for architectural ornaments, to 

 which use it is chiefly appropriated. It is much softer than the fine 

 grained blue and grey limestone on the south-west side of Castle 

 Howard, and has a much more dull and marly fracture: but it bears 

 a strong resemblance to the grey part of the corresponding bed at 

 Pickering, at least to some specimens of it. 



These strata do not abound with organic remains. In some va- 

 rieties, particularly the Hildenley and fine grained limestone, there 



