LOWER GREENSAND. 5 



sand and clay containing small nodules enclosing a Brissus, Ammonites Martini, d'Orb., 

 and detached valves of Exogyra sinuata ; above are three or four ranges of Exogyra 

 sinuata, Sow.; the parallel edges of these large shells, as seen in the cliff, indicate three or 

 four continuous strata, with irregular clusters between them. The second or upper 

 Gryphaea group appears at low water at Shanklin, where the several ranges of Exogyra 

 are seen rising beneath each other. Varieties of this shell appear to me to charac- 

 terize different beds ; for example, the specimens of Exogyra from the Crackers and 

 Lower Gryphaea group present marked differences when compared with shells of the 

 same species from the Upper Gryphaea group. A similar observation has been made by 

 M. Cornuel on the Exogyrce collected by him near Vassy, in France. This geologist 

 assured Dr. Fitton " that he could at once assign each variety of form to a special place 

 in the section of that vicinity." Small fragments of vegetable remains [Lonchopteris 

 Mantellii, Brong.) occur not only in these beds, but nearly throughout the entire 

 formation. 



XL The Cliff-End Sands consist of uniform sand about fourteen feet thick, with a 

 subordinate bed of fossiliferous clay containing Trigonia Dcedalaa, Park., in the lower part, 

 and plant-like pyritiferous concretions in sand and clay in the upper part. 



XII. Foliated Clay and Sand. — Consist of alternations of dark-blue clay and greenish, 

 translucent, siliceous sand, containing nodules of pyrites and large irregular masses of 

 coarse sandstone. These beds are well seen in Walpen and Black-Gang Chines, but no 

 fossils have hitherto been found in them. 



XIII. Sands of Walpen and Black-Gang Undercliff. — This group commences with 

 a bed, about ten feet in thickness, of loose white sand, with thin laminae of gray clay ; 

 this is succeeded by seventy feet of greenish and brownish sand overlain by seven 

 feet of coarse ferruginous sand, with rounded grains of iron-ore in the lower half of 

 the bed, and by twelve feet of alternating sand and clay, making a total of 100 feet. 

 There are only very few fossils in this group — Myacites plicata, Sow., and M. man- 

 dibulata, Sow. 



XIV. The Ferruginous Bands of Black-Gang Chine rise from the shore between Rocken 

 End and Black- Gang Chine, and form the uppermost fossiliferous group of the Lower 

 Greensand ; they are composed of brown and yellow sand, with layers of ferruginous 

 concretions, overlain by a bed of ferruginous sandstone, about five feet in thickness ; the 

 group is about twenty feet in all, and is the equivalent of the zone of Lower Greensand at 

 Parhara Park, and other places in Sussex, and near Sandgate in Kent. The sands in this 

 group are fossiliferous throughout, and the species identical with those found in the Perna 

 bed and Cracker rocks at the bottom of the section. 



