WILMORE : THE STRUCTURE OF SOME CRAVEN LIMESTONES. 161 
part consist of the middle limb of an anticlinal fold. The 
relation of the eastern hills to the folded country is shown in 
the diagrammatic section, Fig. 1. 
Fig 1. 
SECTION FROM PEXDLE TO CHATBURN THROUGH WOKSAW KNOLL. 
a. Base of Millstone Grit Series. Pendle (? Farey's) Grit. 
h. Pendleside Series, Shales with variable limestones and grits, 
c. Carboniferous Limestone Series, with coarse, massive "Knoll" 
Limestone at the top. 
Referring again to the diagram map Plate XIX, it will be 
seen that the distribution of the knolls is intimately related 
to tbe structure of the country, as briefly outlined above. 
It seams clear that the knolls depend more upon the 
" tectonics " of the district than apon any peculiarities of de- 
position, though I do not deny that such peculiarities may 
have existed, and may have had something to do with the 
development of the knolls. 
I propose in this paper to study rather more intimately 
the remarkable series of knolls in the Downham-Clitheroe dis- 
trict. These are marked (A) on Plate XIX. There are five 
at least of these knolls forming a well-marked series, namely, 
the hills of Twiston, Sykes, Gerna, Worsaw, and Worston, though 
I do not see why the low hill of Bellman Quarry, Salt Hill, and 
Clitheroe Castle Hill should not be included. They do not 
form the same " ovoid eminencies," but the limestone itself, 
the bedding, the fossils, the secondary deposits of stalagmite, 
fluor, pyrites, and limonite pseudomorphs after pyrites, are 
precisely similar. Omitting the Castle Hill, which I have not 
been able to study very fully, and beginning at the Clitheroe 
end of the series, the following is a brief description of the knolls. 
(See one-inch Geol. Map, 92, S.W., new series, sheet 68.) 
