166 WIOIORE : THE STRUCTURE OF SOME CRAVEN LIMESTONES. 
succeeding them. Grey or "white" limestones occur not only 
in the knolls at the top of the " massif," but also nearer the 
base of the series exposed in the Chatburn district. The 
Carboniferous Limestone is at least 2,500 feet thick unless 
there is repetition of the beds, and whether there is much 
repetition can only be determined by careful collecting from 
every horizon. I hope it will be possible to work out the 
whole 2,500 feet or so of the limestone massif in zones, as has 
been so ably done by Dr. A. Vaughan for the Bristol area, 
and I commend a share in the work to any members of our 
society who can find time to assist. 
The general succession of the beds from the grit escarp- 
ment of Pendle through the most conspicuous of the knoll hills, 
Worsaw, is as follows 
Millstone Grits. 
Pendleside shales with limestones and grit bands. 
Greyish- white crinoidal limestone. 
More flaggy limestone. 
Flaggy limestones with shale bands. 
Blue and grey massive limestones, with shales. 
Thin bedded dark limestones and shales. 
The beds from the base of the Pendleside Shales down- 
wards contain the same general fauna. 
The succession would then be as in Fig. 3. 
Fig. 3. 
DIAGRAMMATIC SECTION THROUGH THE HILLS BETWEEN THE CRAVEN 
LOWLANDS (a) AND THE LOTHERSDALE ANTICLINAL (b). 
Vertical scale exaggerated. 
The partial isolation of the Worsaw mass and its conse- 
quent knoll-like appearance is partially, if not wholly, accounted 
for by the trend of the old river valleys. There is a manifest 
