14 
DISTRICT OF TABULAR HILLS. 
found about Cave. The lower calcareous grit and coralline oolite are 
extremely well connected from Scarborough round the vale of Pickering 
to Acklam, but they have not been seen further south. The calcareous 
rocks which range close under the wolds of Lincolnshire do not belong 
to this formation, as I have lately had the means of ascertaining. The 
upper calcareous grit covers the coralline oolite at Stonegrave, Oswald- 
kirk, Ampleforth, and Wass bank, and, in lower ground, at Helmsley, 
Kirkdale, and Sinnington * It also occurs, as Mr. Smith informs me, 
in the same manner on Silpho Brow, near Scarborough. 
That all the strata of the tabular hills should be included in one 
formation, appears to me satisfactorily demonstrated by the gradations 
they present between each other. Thus the Kelloways rock changes 
into the Oxford clay, which is still more evidently blended with the 
lower part of the calcareous grit. The calcareous grit and coralline 
oolite above are so harmonized at their junction, that it is not easy to 
mark the exact line ; and the similarity of character between the upper 
and lower beds of calcareous grit completes the evidence which warrants 
the combination of all these strata into one natural group. 
Whoever compares this series of strata with the coralline oolite for- 
mation in Berkshire and Wiltshire, will find them extremely similar in 
the mode of arrangement, in mineralogical composition, and organic 
contents. The features which they impart to the country are much 
alike in both districts, and the whole evidence in favour of their affinity 
is complete and satisfactory. Yet the two districts lie wide asunder, 
and in all the intermediate tract a great portion of the series is unknown. 
From Acklam to the neighbourhood of Oxford, no coralline oolite or 
calcareous grit appears at the surface, (the limestone before mentioned 
in Lincolnshire, is of more recent formation,) and the Kelloways rock 
lias not yet been described between Huntingdonshire and the Humber. 
This should teach us not to undervalue the evidence of organic remains, 
for these are always useful and often necessary guides to determine the 
* See Phil. Mag. and Annals of Philosophy, April, 1828 . 
