Section of the Lower Greensand at Atherfield. 227 



Atherfield, in what has hitherto been considered as the bottom of 

 the lower greensand. But while some of these fossils have been 

 found, in England, only at Peasemarsh and at this place, they are 

 here accompanied by others, which have a considerable upward range 

 in the subcretaceous strata. 



§. The cliffs on the shore between Atherfield and Rocken End, on 

 the east of which latter place the lower greensand first rises, contain 

 comparatively a much smaller number of fossils than the lowest 

 strata just mentioned. Those which are found here, occur chiefly in 

 concretions, due probably to the presence of the organized remains 

 which they include ; but lines of such nodules appear to be distri- 

 buted at intervals throughout the whole series, as far at least as the 

 middle of the cliff at Blackgang Chine. Of these ranges the follow- 

 ing are some of the most prominent, — 



a. A conspicuous group, composed of two parallel ranges of nodules, 

 rises on the shore about half a mile east of Atherfield point, and there 

 forms a slight prominence called " the Crackers," (from the sound 

 caused by the sea during rough weather beneath the undermined 

 cliffs). These nodules consist of a rough concretional calcareous 

 rock (like coarse Kentish rag), which includes in great numbers, 

 Gervillia aviculoides, Thetis minor in beautiful preservation : a pro- 

 fusion of Terebratulte, especially T. sella, Ammonites Deshayesii, 

 Trigonia dccdalea, and other fossils ; — most of which, it is supposed, 

 occur also in the quarry-stone of Hythe. 



b. JExogyra sinuata, with some of the principal varieties of that 

 species figured by M. Leymerie, is of frequent occurrence, both in 

 detached clusters, and in somewhat continuous ranges, throughout 

 the cliffs between Atherfield and Blackgang Chine. 



c. Very large and beautiful specimens of Crioceras (Ancyloceras, 

 D'Orbigny), Scaphites, and Ammonites, have also been found in 

 the face of the cliffs, or within the Chines, on this part of the shore. 

 Of these, Crioceras Bowerbankii* was found in Ladder-chine; Sca- 

 phites gigas loose upon the shore, its precise situation not having 

 been ascertained f. 



§. The author points out, as deserving of especial notice, the rapid 

 and remarkable reduction in the proportion of calcareous matter in 

 the lower greensand of the Isle of Wight and of Surrey, when com- 

 pared with the calciferous district of Kent, from the coast to the 

 west of Maidstone. No continuous beds of limestone occur in the 

 Atherfield section ; while the Kentish rag in the quarries at Hythe 

 and Maidstone cannot be far short of a hundred feet in thickness. 



§. Sandown Bay. — A section corresponding to that of Atherfield, 

 is visible on the east of Sandown Bay, between the fort and the 

 chalk of Culver Cliff. The author had formerly seen there a bed 



* Sowerby, Geol. Trans. 2nd Series, vol. v. 



f Some fine specimens of these large fossils are in the lawn of Capt. Peter- 

 son, near Blackgang Chine; in the museum of Mr. A. J. Hambrough, atSteep- 

 hill Castle ; and in the splendid collection of Isle of Wight fossils, deposited 

 by Capt. Ibbetson in the museum of the Polytechnic Institution. 



Q2 



