224 Geology. 



district consists in the absence of the Insect and Crustacean 

 and the Saurian beds that are more fully developed in the 

 typical sections further south ; and consequently the paucity 

 of Saurian remains ; a single vertebra, and portion of a 

 jaw or tooth occurring here and there, but rarely the whole 

 skeleton. 



The Middle Lias is but poorly developed 



Middle Lias. „ , . . ^ ^ , . . ^ 



near Bath, consisting of a thin series of 

 Clays and Marls. The Marlstone worked so profitably in 

 other parts of England, and of such great thickness, being 

 rarely opened up, but traceable along the escarpment of 

 the hills near Bitton and Bath. It has been proved at 

 Beechen Cliff, Lyncombe Vale, Monckton Combe, St. 

 Catherine, Charlcombe, above Cranwells, and at the Bath- 

 ampton reservoirs. 



This, ■ too, is rarely exposed in our district. 



Upper Lias. , - „ . 



Some years ago the following section, now en- 

 tirely concealed by vegetation, was seen by the writer in 

 company with Chas. Moore. It was on the right bank of 

 the Avon opposite Dundas. 



ft. 



1. Blue Micaceous Marl with thin nodules of ironstone 20 



2. Browni'sh Marlstone with A maculatus. Unicardium 



cardioides, Lingula Beanii abundant, Crustacea 

 and Saurian teeth ... ... ... 1 



3. Blue clay ... ... ... ... 3 



4. Upper Lias. A single bed with yi. Walcottii, A. Ser- 



pentinus, &c. ... ... ... ... i 



5. Gray clay ... ... ... ... 2 



6. Inferior Oolite, sands of ... ... ... 20 



( Vide Som. Arch. andN. H. Soc. Proc, vol xiii.,p. 153.) That 

 rich fish and saurian bed which ought to come in above the 

 Marlstone No. 2 is not represented here, as it is south of the 



