ZONE OF AEGOCERAS PLANORBIS. 



19 



I have placed the sections together for the purpose of comparison : they were first 

 made by my friend, the Rev. P. B. Brodie, F.G.S., and have been often examined since with 

 similar results. These sections show the uniformity which prevails in the Lower Saurian 

 beds of Gloucestershire and Worcestershire, and how much they resemble their correlative 

 strata at Street. 



The late Mr. Dudfield, of Tewkesbury, obtained from the Ostrea-beds at Brockeridge 

 Common, enumerated in the preceding sections, and from other strata occupying the 

 same horizon in the vicinity of that town, a very fine series of Saurian remains, which 

 were all sold and dispersed in June, 1843. From my notes of that collection I find 

 there was a specimen of Ichthyosaurus intermediiis, about 8 feet in length ; the two fore- 

 paddles and a portion of the scapular arch were tolerably complete ; and there were 

 upwards of 100 vertebrse, and many ribs nearly all in place. /. tenuirostris ; 4 feet in 

 length ; the skull, jaws, and teeth were well preserved, and the vertebral column was 

 tolerably complete; likewise one fore-paddle. /. communis; very fine paddles. I. 

 jilatyodon ; large skull, with orbital plates in position. Plesiosaurus Haiohinsii ,- the 

 vertebral column, ribs, and humeri ; and fifty vertebrae in position. 



The Ostrea- and Saurian-htdi?, at Binton, Brockeridge, and Street are overlain by 

 clays and laminated shales, containing Aeyoceras planorhis. As these beds form a most 

 important horizon in the Lias formation, and have a wide geographical distribution in 

 England, France, and Germany, they require to be defined with accuracy, especially as 

 some authors are of opinion that the true Lias commences with this zone of life. 



The relation of the P/«?2or3w-shales to the Saurian beds below is extremely well 

 exposed in the Railway-cutting at Uphill and in the quarries at Street, Somerset; 

 at Binton and Wilmcote, in Warwickshire ; at Brockeridge Common, in Gloucestershire ; 

 at Strensham, Worcestershire ; and to the Bucklandi- or Z2;««-beds above in the sections 

 at Saltford, near Bristol ; Penarth Head, near Cardiff'; Pinhay Bay, near Lyme Regis ; 

 and St. Audreys Slip, near Watchet, Somerset. 



The following section of the beds at Binton was made by Mr. R. Tomes, F.Z.S., 

 from a working now abandoned. A similar exposition, however, was seen in the quarry 

 worked near the former, which I examined and measured with Messrs. Tomes and 

 Kershaw. 



Section of the Zones of Aegoceras planorbis cmd Avicula contorta, at Binton, 



Warwickshire. 



No. 



LiTBOLOGY AND LoCAL NaMES OF BeDS. 



Thick- 

 ness. 



Organic Remains. 



1 



2 

 3 



Light-coloured limestone. " Top rock" 

 or " Whites " 



ft. in. 

 6 

 2 6 

 3 



Ichthyosaurus ; on the upper surface. Insects. 



Light-coloured clay 



Argillaceous limestone. "Top Liveries" 



