22 THE LIAS AMMONITES. 



Beneath the lower bed of the Cidaris-shales are several thin beds of light-coloured 

 limestone, locally called Whetstones, and separated by intermediate shales; then in 

 descending order come the beds known as Grey Burr, Rotten Burr, Eire-stones, Cliff- 

 ledge, Half-foot, One-foot, Red Size, and Anvil-ledge, all separated by thin bands of 

 shale ; on the surface of the limestones and in the shales are many fossils, among which 

 Ostrea liassica forms the dominant shell. The shale above Anvil-ledge contains great 

 numbers of Pullastra arenicola, Strickland, apparently indicating a change of condition 

 in the series of beds which lie below this fossil band. The beds from the Whetstones to 

 the Pullastra-shales represent the Ostrea-series, and from the circumstance of the exposed 

 edges of the rock having weathered to a cream-colour, they form the upper portion of the 

 White Lias. The lower portion of this formation differs both lithologically and palseonto- 

 logically from the upper portion ; it is a compact, earthy limestone, with conchoidal 

 fracture, cream-coloured, and close-grained ; and many of the beds are so fine that they 

 might be used as lithographic stone. Beneath Anvil-ledge are three feet of light-coloured, 

 rubbly beds, containing Modiola minima, Ostrea liassica, Pleuromya Crowcombeia, 

 resting upon eighteen inches of White Lias ; then follow a series of irregular beds, with 

 thin partings, twelve feet in thickness, which overlie a bed, twenty-one inches thick, 

 of fine, white limestone, resting on a like thickness of shale ; beneath this is a bed of 

 smooth, regular, fine, white limestone, six feet thick ; then a bed of shale ; and at the 

 base of the series is a band of Cotham marble or Landscape-stone. The lower portion 

 of the White Lias from the Pullastra-shales downwards represent, I believe, the upper 

 beds of the Jvicula-contorta-zone ; there are many fossils in the limestones, which have 

 not yet been determined. I have found casts of Cardium Rhceticum, Monotis decussata, 

 Pullastra arenicola, and shells of Pecten Valoniensis. Unfortunately the fossils are mostly 

 in the form of moulds, and for this reason we must wait until better specimens are 

 obtained. The lower portion of the White Lias series is only seen in Mr. Eowler's quarry 

 at Up-Lyme. 



The coast-section at Pinhay Bay is a complete repetition of the Up-Lyme quarries ; 

 the Cidaris-shales are well exposed at low water during spring-tides, and from them 

 are obtained all the Echinidce found in the section. I know of no Asteriadce in these 

 beds. 



In Gloucestershire this zone is well exposed at Brockeridge Common, and at Wainlode, 

 in a quarry on the right-hand side of the Gloucester Road, between Hartpury and Ashel- 

 worth, and at Elmore, in quarries near the Old Kennel. 



In Glamorganshire it is seen in the fine coast -section at Penarth Head. In Somerset- 

 shire, in the cutting of the Great Western Railway at Saltford ; in the Uphill Cutting on 

 the Bristol and Exeter Railway ; in the coast-section at St. Audreys Slip, near Watchet ; 

 and in all the quarries at Street. 



In Worcestershire it is found at Strensham ; and in Warwickshire at Binton, Grafton 

 and Wilmcote. 



