THE LOWER OOLITES HEAR BRISTOL 167 
Cidaris bradfordensis. 
Serpula grandis. 
Terebellaria raniosissima. 
Diastopora foliacea. 
Berenicea diluviana. 
,5 archiaci. 
,, scobinula. 
Stomatopora dichotoma. 
Theonoa distorta. 
The fossils of the Forest Marble are, as usual, very much 
crushed and difficult of extraction ; Ostrea Sowerbyi, 
Pecten vagans, and Trigonia detrita can, however, be 
obtained in good condition. 
Although there is evidence that the Bradford clay 
extends from Cirencester in the north to the Dorsetshire 
coast in the south, as a formation it is local and insignificant. 
Messrs. Reynolds and Vaughan were unable to separate 
a Bradford clay horizon at the eastern end of the Sodbury 
Tunnel, where the Great Oolite and Forest Marble series 
are well developed. No specimens of Dictyothyris coarc - 
tata nor of Apiocrinus were found,, but with these excep- 
tions, they say A “It would be utterly impossible to 
separate the top beds of the Upper Great Oolite from the 
Bradford clay, on palaeontological grounds.” 
It is evident that, locally, there was some pause in 
deposition between the Great Oolite and Bradford clay, 
and where this occurred the Crinoids flourished on the 
floor of the Great Oolite, becoming encrusted, as we find 
them to be, with Serpulse and Polyzoa before the muddy 
sediments of the Bradford clay were laid down. In other 
localities, where there is no distinctive evidence of Bradford 
■clay, there was probably no pause in deposition, no growth 
of crinoids, and no accumulation of organic remains to 
form a fossil bed. 
N 
# 
1 Q.J.G.S., vol. Ivii. p, 746. 
