fitton's section at atherfield. 31/ 



Species in the Perna Bed^ at Redcliff near Sandown Bay. 



Area Raulini. Panopsea plicata (var.). 



Astarte obovata (Beaumontii). Pecten circularis. 



Avicula depressa. quiiiquecostatus ? 



Cardium sphaeroideum. Perna MuUeti. 



Corbis corrugata {SpJiara), alaeformis. 



Cucullaea Cornueliana. Ricordiana ? (? tetragona of 



Cyprina angulata (young). Geol. Trans, iv. p. 130.) 



Gervillia aviculoides. Thetis ? 



linguloides. Trigonia alaeformis. 



alaeformis {Perna, Sow., very Dasdalea. 



good specimens). Terebratula Gibbsiana. 



Gryphaea sinuata, Sella. 



(small). Tellina angulata. 



harpa. Trochus. 



Modiola legumen {simplex, Leym.). Turbo. 



Mytilus lanceolatus. (Several oblongbivalves, indistinct.) 



Modiola aequalis. Ammonites. 



Panopaea plicata. 



I do not know whether this group or bed is divided here, as it is at 

 Atherfield, into two parts; but above it the *' Atherfield clay" is 

 here perfectly distinct ; and my collector, who is well-acquainted with 

 the strata, found, nearer to the base of Redcliff, a nodule containing 

 moulds of a spiral univalve {Rostellaria BobinaldinaV) which he 

 considered as belonging to the " Crackers." 



After passing westward over the slight curve formed by the 

 Hastings-sands, as we advance on the coast towards Shanklin, the 

 Perna bed ought to be found at very low tides above the Weald clay 

 beneath the Barrack-hill ; and here my collector did find a Panopsea 

 in what he knew to be the Perna group. A fault (at Small-Hope 

 Point), by which the continuity of the strata is broken, and which I 

 had mentioned as having been pointed out by Sir John Herschel*, was 

 again discovered here, and carefully examined by Captain Ibbetson ; 

 who has informed me, that in a quarry not far from the shore, within 

 the cliff of sand-rock between the Barrack-hill and Small-Hope Chine, 

 he found specimens of Crioceras, in the site where they were to be 

 expected. The cliffs thus far are so much decomposed that the strata 

 are scarcely distinguishable ; but between the shoulder or prominence 

 at Little-Stairs Point and Shanklin Chine, a bed, of which a large 

 surface is uncovered at low water, corresponds to one of those in the 

 second Gryphsea group No. 36, beneath Walpen High-chff. This, 

 which, as it is here seen, may be truly called an ancient oyster-bed, is 

 studded with clusters of GryphcEa sinuata, vdth Ostrea prionota, and 

 has precisely the appearance that would be exhibited if any of the 

 beds of Gryphsea, the edges of which are visible on the west of ClifP- 

 end, &c., were extensively laid bare. 



The " oyster-bed" is an excellent point of recognition. The next 

 stratum above it, which forms a shelf or narrow undercliff at the foot 

 of the adjacent cliffs, is evidently a continuation of the foliated dark 

 clay and sand (No. 40) of the shore between Black-Gang Chine and 



* Geol. Trans. Second Series, vol. iv. pp. 192, 193. 



VOL. III. PART I. Z 



