199 



very closely connected with the lov/er part of the indurated stratuili 

 (4) : but after exposure even for a short time to the air and sea, the 

 soft matter of (3) is rapidly removed, leaving the firm mass of (4) 

 detached and prominent ; and this being undermined, appears upon 

 the shore in rudely quadrangular detached blocks. 



The fossils of the lowest clay (3) appear to be the same, though the 

 species are less numerous, with those of (4) above it. The most re- 

 markable amongst them i.s Perna Mulleti. Mya and Panopaa, pro- 

 bably of more than one species, are especially numerous, even close 

 to the very junction of the Wealden : and with these were Area 

 Raulini, Mytilus lanceolatus, Pinna sulcifera, Pecten quinquecostatus , 

 and P. striato-costatiis (Goldfuss). 



4. The bed of firm, subferruginous and somewhat calciferous stone 

 which next succeeds, formed, when the author first examined this 

 place (in 1826), the most prominent feature of the cliffs : everything 

 beneath, to a depth of about ten feet, being deeply concealed by 

 ruin. It was now distinctly seen that the bottom of this remarkable 

 bed is not more, at the utmost, than three feet from the top of the 

 Wealden. By its greater firmness it contributes to sustain the cliff, 

 the mass of which it traverses obliquely in rising westward ; and 

 from the base of the projecting land or point of Atherfield it runs 

 out into the sea, declining very gradually, and forming a dangerous 

 reef called Athei-field ledge. Though its average thickness is not 

 more than 2| feet, this bed abounds very remarkably in fossil remains, 

 among which are several of the species figured by M. Leymerie in 

 his memoir on the geology of the Aube, and of those found by Mr 

 Austen at Peasemarsh, in Surrey. 



Ostrea (new species). Pecten quinquecostatus, 



Spatangus (three or more species). striato-costatus. 



Mya mandihula. ohliquus {interstriatus 



Pholadomya acutisulcata (Leym :). Leym :). 



Prevosti (Leym :). Gryphcea sinuata. 



Corbula striatula. Terehratula sella. 



SphcBra corrugata. (three or more other .?p.). 



Thetis minor. Orbicula Icevigata (Deshayes). 



Trigonia dcedalea. Katica {Ampullaria) laevigata 



Fittoni. (Leym.). 



(tw^o new species). Pleurotomaria gigantea. 



Gervillia aviculoides. Nautilus radiatus. 



Pinna sulcifera. Ammonites Deshayesii (Leym :). 



Perna Mulleti. (four or five species). 



alceformis. with many other genera. 



.5. Immediately above the stone-bed (4), is a thick mass of nearly 

 uniform clay, with many of the pro])erties of fuller's earth. It is di- 

 vided apparently into two principal strata, each not less than fifteen 

 feet in thickness ; and these seem to be succeeded upwards by other 

 argillaceous beds, which were so much obscured by debris as not 

 to be traceable. The fuller's -earth is either of a lavender-blue or of 

 a drab colour; it contains concretional portions (not seen in sitxi), 



A^OL. IV. PART I. P 



