WEALDEN BEDS. 7 



the " Pine Raft " is of wide range, or that the horizon at which 

 it occurs should be recognisable when the trees are not present. 

 There is no evidence that any of the trees in this or any other 

 part of the Wealden series grew upon the spots where they are 

 now found. 



In the cliffs of this neighbourhood there have been found also 

 the cones to which more special reference is made in the fossil 

 list on p. 258. 



Mantell records also the occurrence of Clathraria Lyellii as a 

 pebble on the beach of Brook Bay. 



The large freshwater shell, Unio imldensis, was first observed 

 by Mantell "in the sandy clay beds immediately above the fossil 

 forest " {op. cit., p. 94). It occurs also in some hard irony con- 

 cretions, which have fallen to the beach on the west side of 

 Sedinore Point. 



Fig. 4. A large nnmber of reptilian bones 



Unio valdensis, Mant. ^^"^^ has been obtained from the cliffs. 

 Those on which the species Iguanodon 

 Seelyi was founded were obtained by Mr. 

 Hulke in the small chine 180 yards 

 south of Brook Chine.^ Oiniithopsis 

 Hulkci also occurred in Brook Bay, and 

 footprints, believed to be those of an 

 Iguanodon, have been found 600 yards 

 to the west of Brook Point, and near 

 Sedmore Point by Mr. Beckles.t The prints occurred as casts, 

 attached to a thin bed of hard sandrock on the shore at low 

 water. For further information on the fossils the reader is 

 referred to the list on p. 258. 



As we proceed from Brook either westwards to Compton or 

 eastwards to Atherfield, an ascending section in the same beds is 

 provided in the cUff, the distance to be travelled in the former 

 case before reaching the top of the Wealden beds being less on 

 account of the greater steepness of the dip. We will first examine 

 the cliffs westwards, as far as the great slip which marks the 

 position of the Atherfield Clay (Plate II.). 



On rounding the Point we find the cliff composed principally 

 of red and purple marls for a distance of about 700 yards, the 

 thickness of strata amounting; to 439 feet. In the marls there 

 occur beds of sandstone often conspicuous from their whiteness, 

 and a few green bands containing lignite. Passing over some 

 thin and impersistent sandstones near the Point, we meet the first 

 noteworthy bed 170 yards further west, where there is seen in 

 the upper part of the clift' a grey clay packed with lignite, resting 

 on a white sandstone 5 feet thick, but thinning away westwards. 

 This is overlain by purple and variegated clays, and 100 yards 

 westwards a second bed of white sand-rock, 7 feet thick, succeeds. 

 A third bed, 16 feet thick, is seen on the east side, and a fourth, 



* Quart. Journ. Geol. Soc, vol. xxxviii. p. 135. 1882. 

 t Ibid., ▼ol. xviii. p. 443. 1862. 



