46 C.C. NATURAL HISTORY SOCIETY. 



much of the Continent of Europe. So that in the main the Lias 

 fossils found in the Cheltenham neighbourhood do not differ in 

 any noteworthy degree from Lias fossils found |in many other parts 

 of England, France, Germany, and so forth. A collection of Lias 

 fossils is most necessary, and that the species should be repre- 

 sented by fossils obtained from the neighbourhood of Cheltenham 

 is desirable ; but, broadly speaking, except for some special work, 

 such local fossils have not a particular interest. 



The case, however, is very different in regard to the Inferior 

 Oolite rocks, whereof the Cotteswold Hills surrounding Chelten- 

 ham are mainly composed. Their fossils have a special character 

 of their own. 



Towards the close of the Liassic period the accumulation of 

 deposits would seem to have produced, in certain places, a shallow- 

 ing of the sea. More or less contemporaneously, perhaps, some 

 earth-movements occurred, elevating certain areas of the Liassic 

 sea-bottom, so that its rocks formed land when some of the 

 Inferior Oolite strata were being laid down. The Cotteswold area 

 of the Inferior Oolite sea was presumably cut off from direct com- 

 munication with the South England and Continental areas of the 

 same sea. And its eastward connection with any other sea seems 

 to have been disturbed. So there was left to it only a northward 

 communication — over Cheshire and beyond, past the North of 

 Ireland. But of that we shall never know anything, for from 

 Leckhampton Hill to the mouth of the Dee all the Inferior Oolite 

 rocks have been destroyed by denudation during the Cainozoic 

 Era. 



There was, then, a land-locked sea of the Inferior Oolite 

 opening towards the north, and cut off from communication to 

 south and east by some barriers. Direct westward communication 

 of the Jurassic sea there was not — any such communication had 

 always been prevented by the great land-mass of Ireland, Wales 

 and the Malverns. 



In this land-locked Inferior Oolite sea special local conditions 

 obtained. It was a region where outside influences were little felt. 

 Consequently the species pursued their own development ; and 

 the fauna entombed in the Inferior Oolite rocks of the Cheltenham 

 district has special local features. Many of the species are not to 

 be found elsewhere in England or on the Continent. The best 

 example of a local species abundant here but not to be found 

 elsewhere is Terebratula fimbria of the Oolite Marl. But many 



