1845.] MANTELL ON THE WEALDEN OF THE ISLE OP WIGHT. 91 



especially the anastomosing of the lower veinlets, more distinctly 

 than our American specimens. With these they agree so well, that 

 I cannot but consider them as the same species ; and therefore, al- 

 though the specific name of emarginatus is certainly not applicable, 

 I think myself obliged to retain it, to avoid the confusion arising 

 from a multiplication of synonyms. 



The Pecopteris G^6/>jt?er^2of Mr. Morris, from the Permian system 

 of Russia, comes very near, in several respects, to P. emarginata ; 

 but the insertion of the pinnae on the stalk appears to be different, 

 and the veinlets are generally forked, whereas in our plant they 

 are always simple. 



DESCRIPTION OF THE PLATES. 



Plate VI. 



Figs. 1, 2, 3, Pecopteris emarginata, natural size. 

 4, 5, „ „ magnified. 



Plate VII. 



Figs. 1, 2, 3, Pecopteris elliptica, natiu-al size. 



4, „ „ barren pinnules magnified. 



5, „ „ fertile pinnules magnified. 



2. Notes on the Wealden Strata of the Isle of Wight, with an 

 account of the Bones of iGUA^OBoiiis a7id other Reptiles discovered 

 at Brook Point and Sandown Bay. By G. A. Mantell, Esq., 

 LL.D., F.R.S. &c. 



The author commenced with some remarks on the general geolo- 

 gical structure and picturesque features of the Isle of Wight, and 

 then proceeded to direct special attention to some extensive ledges 

 of low rocks visible from a considerable distance, and occurring 

 seaward of Brook Point, a low promontory near and to the east of 

 Compton Bay. The face of the cliff is here formed by the bassetting 

 edges of the Wealden clays and sands, which alternate with occa- 

 sional layers of argillaceous shelly limestone, rolled blocks of which 

 are strewed along the beach. This limestone is formed of the shells 

 of Paludina, Cyclas and other Wealden species, and is in every re- 

 spect identical with the Petworth marble and Ashburnham beds of 

 Sussex. 



The cliff at Brook Point is between thirty and forty feet high, 

 and is capped by an alluvial bed of loam, sand and gravel. It is 

 composed of beds of laminated clay and shale, with sands and sand- 

 stones of a bluish and reddish-gray colour, and these are inter- 

 spersed with layers and isolated masses of lignite and lumps of iron 

 pyrites. 



East of the Point a chine or chasm occurs, from the summit of 

 which a stream gushes out and dashes down the face of the cliff to 



