FROM THE GREAT OOLITE. 189 



placed even generically. I may allude, however, to one which has a 

 dendroid growth, a thick and wrinkled epitheca, increase by lateral 

 gemmation, and denticulated septa which pass into a central mass 

 which has something the appearance of a papillose columella. 



CoNCLTJSioir. 



The beds of massive and nearly unfossiiiferous building- stone 

 around Bath indicate a period of continuous deposition which was 

 inconsistent with coralline growth. At the conclusion of this 

 period, when there was a pause, the condition became so far 

 favourable as to be productive of coralline life, and in considerable 

 variety and plenty. 



The coral-beds exposed on the Farley and Hampton Downs con- 

 sist of a whitish mudstone, in which the corals are imbedded, many 

 of them showing, by their incrusting and delicate Bryozoa and 

 Serpulae, perfect in their details, that they lived and died where they 

 are now found. Such has been the case with some of the tall 

 dendroid examples of Microsolena exceha^ which, attaining to a 

 height of a foot and a half, and having a bush-like form, may still 

 be seen in the Farley-Down section attached to the substance on 

 which they grew when the sea of the Great Oolite washed over 

 them. It is probable that the coral-beds of these localities, like 

 other oolitic ones, were not of great extent ; for on Combe Down 

 other conditions prevail. The coral-bed there, though holding the 

 same position, presents a very different appearance. The corals are 

 scattered in it in varying degrees of abundance. It is distinctly 

 oolitic, and does not afford the least evidence of having been 

 the place of growth of the corals. On the contrary, they have 

 much the aspect of derived fossils. Yet this bed, from its strati- 

 graphical position, and from the number of corals it contains, is 

 evidently of the same age as those of .Farley and Hampton Downs, 

 and may perhaps have been the result of a wash from some near 

 coral-bank. 



Correlated with the coralliferous deposits of the Great Oolite of 

 Oxfordshire, those around Bath probably correspond with the one 

 exposed at Caps Lodge, near Burford. At that place, and on 

 Farley Down, are patches of Forest Marble which overlie the coral- 

 beds and appear to hold nearly the same position in relation to them 

 at both those places. Hence the probability of their being on the 

 same geological level. 



From the frequency of sponges associated with corals in the Butts 

 Quarry, Hampton Down, and at Farley Down, it is probable that 

 Mr. Moore's sponge-bed at Hampton Eocks is the equivalent of the 

 lower part of the coral-bed, which at that place contains more 

 sponges and fewer corals. 



Of the probable age of the coralline deposit in the Lime-kiln 

 Quarry, near Cirencester, I can say nothing. 



Q.J.G.S. iS"o. 162. p 



