50 



come from the chalk districts, and with the various oolitic debris 

 constitute the remainder of the deposit at Freshford. 



West of Bath, at Newton and Saltford, neai- the outcrop of the 

 lower lias, the gi-avel contains many blocks of that formation, which 

 are associated with debris derived from the coal measures. 



The Larkhall gravel pit is the one which is chiefly worked near 

 Bath. It is not only very deep, but from the variety of its 

 contents is the best in the district for study. 



In the section, which has already been given, it will be obsei-ved 

 that between the two deposits of gravel there are intei-posed thick 

 beds of laminated marls. Probably they are only local, and like 

 other intercalated beds in the gi-avels soon die out. They shew a 

 period of repose between the deposits of the two thick beds of 

 gi-avel. From the lithological character of these marls, and from 

 their chiefly containing organic remains of the age of the frdler's 

 earth, there is little doubt they have been derived from this forma- 

 tion, and brought down from the escai-pments. I have lately 

 remarked that moUusca of the age of the gi-avels are rare, but it 

 is not so in this instance, for there are bands in these marls 

 which contain enormous numbers of the little land shell, Ptipa 

 marginata, which have been washed down with the marls from the 

 hills, and there are also, though very rarely, Succinea oblonga and 

 jjelix. — The mammalia in this pit, to be hereafter noticed, are 

 most abundant in the under portion of the lower drift. 



The following derived fossils occur at Larkhall. 



From Fuller's Eaiih. 

 Anabacia orbulites 

 Avicula echinata 

 Goniomya angulifera 

 Modiola renifoi-mis 

 Nucula 



Rhynchonella varians 

 Terebratula omithocephala 

 Ostrea acuminata 

 Pholadomya deltoidea 

 Lima proboscidea 



From Inferior Oolite. 

 Astraea and other corals 

 Belemnites canaliculatus 

 Pentacrinites 

 Trigonia costata 

 Terebratula perovalis 

 Thecidium triangularis 



From U2)per Lias. 

 Ammonites Walcottii 



Serpulte 1 » serpentmus 



