186 Reports and Proceedings. 
Gloucestershire, with the town of Cheltenham in the foreground, 
situated as it were in a sheltered bay of the Cotswold Hills. The 
scene was bounded on the north-west by the faint outlines of the 
Malvern range, which, though infinitely older in a geological point 
of view than the Cotswolds, is intimately associated with them as 
forming at no very remote period the western boundary of the sea 
which then rolled from what is now the British Channel to the Irish 
Sea. Indeed the ‘ancient Straits of Malvern’ is now an expression 
with which few geological readers are not familiar. Had the day 
been fine, the Old Red Sandstone hills of the Black Hills, and the 
blue outlines of many Welsh peaks, would have been discernible. 
The interesting geological features of the extensive scene were here 
laid before the party in a remarkably distinct manner. The flat, 
agricultural, and well-wooded district is Lower Lias Clay, which 
beneath Cheltenham is said to be about 600 feet in thickness. Above 
this, just at the fork of the hills, a gentle slope leads up to a well- 
defined platform. These are the two divisions of the Middle Lias, 
the upper or rock-bed forming the terrace above mentioned, while 
the sandy beds shade off gradually into the plain below. ‘The next 
member of the Lias is a layer of blue shale and clay, which on the 
other side of the hills throws out the ‘Seven Springs,’ and may be 
generally traced better by the water which escapes from the line of 
junction with the upper strata than by any evidence to be obtained 
from the face of the hill. ‘The overlying deposit, only a few feet in 
thickness, is a most remarkable bed, and one which has afforded a 
considerable number of organisms which do not pass upward into the 
Oolite rocks above. This has been termed by some the ‘Ammonite- 
bed,’ but it is now familiarly known to geologists as the ‘Cephalopod- 
bed,’ and is now taken as the upper member of Liassic formation, 
and as one of our best illustrations of the breaks which frequently 
occur in the rocks, and where a total change in the fossil remains, 
even within a few inches of vertical space, indicates a vast lapse of 
time which must have intervened between the formation of adjacent 
deposits. This peculiar bed has been traced from Cheltenham to the 
Dorsetshire coast, and also into the North of France. The Oolite 
series, well seen in the Leckhampton quarries, consists, in ascending 
order, of (1) pea-grit, so called from the large particles of carbonate 
of lime of which it is composed; (2) lower freestone, a considerable 
thickness of softish, white stone, easily worked, and showing the 
oolitic character very clearly; (3) a thin layer of marl; (4) the 
upper freestone, much similar to the lower; and (5) the ragstone, 
already mentioned. But not only are the above geological features 
presented to view from the summit of this eminence; the evidences 
of the nature of the changes by which the present configuration of 
the district was originally produced are clearly exhibited. The Lias 
plain is dotted here and there by rounded, isolated hills, having the 
same structure as the typical Leckhampton mass, and evidently due 
to denudation. At one time no doubt they existed as islands in the 
ancient sea whose eastern beach was on the flanks of what is now 
the Cotswold Range. But attractive as was this vantage ground 
