18 



THE LIAS AMMONITES. 



intermedius, Conyb., from a bed of light-coloured Lias at Haselgrove, near tlie " Polly ;" 

 and the late Mr. Dudfield collected several very fine skeletons of Ichthyosaurus tenuirostris, 

 Conyb., I. intermedius, Conyb., and /. communis (?), Conyb., with bones of Plesiosaurus 

 Hawkinsii, at Brockeridge Common, and from similar beds in other localities near 

 Tewkesbury ; and I possess several vertebrae of Plesiosaurus rugosus, Owen, which were 

 obtained from a bed of Lower Lias at Woolridge, near Hartpury. 



The junction of the Lower Lias with the red marls of the Keuper in the Vale of 

 Gloucester is, in general, indicated by a low escarpment, facing the west. At Brockeridge 

 and Defford Commons this natural boundary is exceedingly well marked, and between 

 these tvFo localities are several quarries which expose to a greater or less extent the beds 

 how under consideration. The presence of Aegoceras planorbis in the upper strata of 

 these sections has enabled me to correlate the beds beneath with the corresponding strata 

 at Street, in Somerset, and at Biuton, Grafton, and Wilmcote, in Warwickshire. 



Section of the Planorbis-, Ostrea-, and Saurian-hedis at Brockeridge and Defford Commons. 



Zones. 



Strata and Organic Remains. 



Brockeridge. 



1. Light-coloured clay 



2. White laminated limestone 



rub," Strensham 



3. Brown laminated clay, with compressed white shells of Aegoceras 



" First rub," Brockeridge ; " Chance 



Blue argillaceous limestone^ „ , , , ,, „ , • ■, 

 _ , , n / " Double rub, Brockeridge : 



Brown shaly clay !■ 



_, ,. V " Double nurr, Strensham. 



131 u^ limestone j 



Dark clay, with Saurian remains. "Yard clay" 



Hard blue limestone. Ostrea liassica on the surface of the 



rock. This^bedis called "Red nurf " at Brockeridge, "King's 



nurf " at Strensham 



Dark clay. The second bed of " Yard clay " at Strensham 



Blue limestone. The "Queen's nurf," Strensham 



Blue clay 



Hard blue limestone, with Modiola minima 



Paving-stone, separated by an inch-band of clay 



Dark shale. Vertebrae of Icthyosaurus, tests and spines of 



Cidaris Edwardsi, Hemipedina Tomesii, and Fishes' scales 



Hard blue limestone, in square blocks. "Brick-bed" 



Dark shale 



Insect-limestone of the Rev. P. B. Brodie,F.G.S.; a hard argillaceous 



limestone, containing the Elytra and other remains of Insects... 



Blue shale 



Light-blue limestone, with Cardinia ovalis, Macrodon Hettangiensis, 



and Astarte obsoleta 



ft. in. 

 3 



4 



ft. in. 

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