T9 



of it, as Hearne Bay and the Old Haven, near Bishopstone, have 

 completely lost the features to which they owe their appellation. 

 He then enters into a minute detail of the London and plastic clays, 

 of which the district is principally composed. He shows that the 

 former constitutes the whole of the cliffs from Whitstable marshes 

 to Hearne Bay, and the upper part of that to the eastward of it. 

 The clay he divides into two portions J the higher contains much 

 sand and green earth, and is occasionally marked with patches 

 and streaks of liglit blue or green clay; and the lower preserves 

 the usual characters of the formation. The only organic remains 

 which he noticed were fragments of wood, teeth of fishes, and por- 

 tions of an Encrinite and of Pentacrinites sub-basaltiformis. Iron 

 pyrites and selenite are stated to abound in every part of the clay, 

 and amber and jet to be occasionally found in it. A minute de- 

 scription is given of the Septaria, which are said to be very numerous 

 and to have the surface often covered with small ramifications re- 

 sembling branches flattened by pressure. 



Of the plastic clay formation only the sandj' portion is said to occur 

 on the coast, it first appears to the east of Hearne Bay rising from 

 beneath the London clay at an angie of about 5°, and extends to 

 Birchington, where it is succeeded by chalk. It contains beds o f 

 pebbles and friable sandstone inclosing shells. Sectional lists are 

 given of the cliff near Bishopstone, and of that on which the Recul- 

 ver Towers are situated ; and the author rectifies the error in the 

 " Outlines of England and Wales," where it is stated that the Re- 

 culver cliff is composed of London clay. The fossils mentioned in 

 the paper are confined to the genera Venus, Cerithium and Trochus, 

 and the remains of fishes. The chalk which forms the coast from 

 Birchington to the North Foreland is mentioned only for the pur- 

 pose of showing that it declines to the westward at the same angle as 

 the superior formations. A bed of brown loam containing a ^ew 

 flints is described as covering the surface of the London and plastic 

 clays, and to be thickest in those parts where the cliffs rise to the 

 greatest height. The vast accumulation of bones in the oyster-bed 

 opposite Swale Cliff" is also described, and among those obtained by 

 the author are the remains of the elephant, horse, bear, ox and 

 deer, 



A paper was afterwards read, " On the several Ravines, Passes, and 

 Fractures in the Mendip Hills and other adjacent Boundaries of the 

 Bristol Coal-field, and on the geological Period when they were ef- 

 fected," by the Rev. David Williams, F.G.S. 



The district included in this memoir comprehends the western 

 portion of the Mendip Hills, and the western and north-M'estern 

 boundaries of the Bristol coal-field. It presents a series of lofty ridges 

 composed of mountain limestone and traversed by deep transverse 

 ravines which connect the valleys on the opposite sides of the ridges. 

 The author describes, in great detail, the characters, both physical 

 and geological, of each ravine; and shows that in consequence of 

 their being filled, in part, with horizontal beds of dolomitic conglo- 

 merate, red marl, and lias, they were formed previously to the 



