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PROCEEDINGS OE THE GEOLOGICAL SOCIETY. [Feb. 29, 



the bed beneath the marl is a band of hard calcareous rock, which 

 appears to be very persistent; on its upper surface He immense 

 numbers of Pecten Valoniensis, Defr., closely compressed together, 

 but in a bad state of preservation. "With these are associated a fine- 

 ribbed Anomya, and other shells in a fragmentary state. Beneath 

 this Pecten-hand lie many feet of dark shales, and then another 

 stony band with Pecten Valoniensis, underlain by shales and layers 

 of ripple-marked micaceous sandstone, with Avicula contorta, Portl., 

 and Pullustra arenicola, Strickl. The Bone-bed occurs likewise in 

 this section, although I failed to find it in situ, from the weather 

 having been unfavourable during the previous day. Between the 

 sandstone and the Keuper is a black shale 2 feet thick. The upper- 

 most bed of the Keuper, on which the shales repose, is a very hard 

 rock. The greenish-grey marls of the Keuper, with a few purple- 

 coloured bands, measure about 30 feet. Beneath these is a band of 

 pure white gypsum, succeeded by other variegated, red, and greenish 

 marls, of which 30 feet or more is seen. 



Section at Uphill Cutting, near Weston-super-Mare, on the Bristol 

 and Exeter Railway. — The Avicula contorta beds in Somersetshire 

 are exposed by a railway- cutting at Uphill near "Weston-super- 

 Mare, and on the coast at Watchet. At the former locality I ob- 

 tained a section of the Lias resting conformably on the marls of the 

 Keuper ; but it has been suddenly upheaved and inclined to a high 

 angle by the intrusion of Carboniferous Limestone, which has been 

 thrust upwards by a mass of igneous rock seen in situ near the level 

 of the railway. The disturbance has been quite local, as the red 

 marl is only slightly disturbed at a short distance from the Car- 

 boniferous Limestone. 



Zone of 



Ammonites <^ 

 planorbis. 



a. Alternate beds of light- coloured Lias ft. 



limestone and shales, inclined at an 

 angle of 40°, much fractured and dis- 

 turbed 10 



b. Dark-greyish laminated shales, inter- 



stratified with thin bands of limestone ; 

 between the laminse of the shales are 

 found Ammonites planorbis, Sow., com- 

 pressed, and having the shell white . . 



c. Band of Lias limestone 



d. Dark shale, with Ostrea liassica, Strickl. 



e. Band of Lias limestone 



/. Dark shale, with Ostrea liassica,, Strickl. 

 g. Beneath the preceding bed are from 



twelve to fourteen beds of limestone 

 and shales or marl (a bed of limestone 

 and a bed of marl alternating). Ostrea 

 liassica and Modiola minima are found 

 sparingly in the beds 12 



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