KErORTS or MELTIKGS. I3l 



few words, tlie form of the range, tlie gentler slopes at tlic base 

 of the hills, the steeper cliffs above, the projecting spurs, the 

 retreating bays, the detached outliers like Bredon Hill, which 

 was full in the face of the audience, or Churchdown Hill on their 

 left, and EobinHood behind, — all these features are the product of 

 two elements, viz., on the one hand the nature of the strata, and on 

 the other the action of denuding agents. The base of the Hills 

 and floor of the valley were of L. Lias clays, and limestones; on 

 these rested the harder beds of the Middle Lias and the Oolite 

 rocks; these latter stand out in steeper masses owing to their 

 superior hardness, while the clays are washed away and moulded 

 by rains and tides. It was the patch of Oolite and bluffs of 

 Marlstonc of Eredon Hill which were the cause of that hill's 

 existence; these had protected the lower clays against denudation 

 and its consequences. 



Turning now to the Inferior Oolite, of which Leckhampton 

 Hill is composed, Dr. "Wright explained that the wonderful series 

 of beds, over two hundred feet thick, contained different fossils 

 in different levels, and the labours of palaeontologists had shown 

 (of whom we may^ add Dr; "Wright is perhaps the chief) that 

 these had a definite position in relation one to the other. The 

 most characteristic group in the secondary rocks were Ammonites. 

 Here producing three from his bag. Dr. "Wright enlarged on the 

 remarkable persistence with which these distinguish different 

 levels or horizons. These were Amm. Murchisonce, which is 

 found in the lower beds of the Inferior Oolite ; A. Humphresianus, 

 which characterises the beds above; and thirdly, A. Farkinsoni, 

 which distinguishes t'he top beds of the series. These always occur 

 in the same order : their relative position is constant not only in 

 England, but in Erance, and as far as Suabia, where the 

 lecturer's friend, the late Dr. Oppel, had found it in the same 

 position, and accompanied by the same fossils, as we find with 

 it in England. These Ammonites are therefore of the greatest 

 importance to palaeontologists. 



Passing then from the objects, uses, and application of 



