1871.] JTTDD PUKFIELD FORKATIOJf. 219 



in the €owleaze series the argillaceous element preponderates, the 

 Barnes beds are in great part composed of sand or sandstone, with 

 subordinate bands of clay. The following is the succession of beds 

 in Brixton Bay. 



(a) Very hard greenish-white sandstone, ^vith many nodules 



and veins of pyrites ; shells numerous in its upper part 1 to 2 feet. 

 (5) Less hard coarse greenish sandstone forming a ledge 



above the beds below 4 to 6 feet. 



(c) Yellow false-bedded sand slightly ferruginous in its 



upper part, carbonaceous in places 25 to 30 feet. 



{d) The lower portion of the last graduates downwards into 



interlaminated sands and grey micaceous sandy clays... 15 feet, 



(e) Yellow and white sands 3 feet 



These beds rest on the ordinary variegated strata of the Wealden, 

 which are exposed to a thickness of from 300 to 400 feet ; but their 

 base is not visible in the Isle of Wight. 



The sandy beds of the Barnes series usually contain but few 

 shells. The top band of sandstone exhibits Cyrena and Unio in 

 abundance, but, owing to the hardness of the matrix and the decom- 

 posed condition of the shells, the fossils are very difficult of extrac- 

 tion. In places the beds contain much carbonaceous matter, with 

 seams of lignite and masses of wood converted into jet or pyrites. 

 One band has yielded marine shells, including oysters, Cardium, 

 casts of Trigonia, and several univalves. The beds of the Barnes 

 series have furnished to local collectors a rich harvest of reptilian 

 bones *. 



It seems not improbable that the thin beds (A) at the top of the 

 section in Punfield Cove represent, in a very attenuated condition, 

 the Cowleaze series of the Isle of Wight, while the beds below 

 (B and C), are an expanded form of the Barnes series. 



2. Compton Bay. The Punfield strata are here highly inclined, 

 and are broken up by several faults. They are well illustrated in 

 the section of Professor Forbes and Mr. Bristow f. The Cowleaze 

 series, with its Cyrena- and Paludina-hmestones and "beef" and 

 " cinder " beds, is well exposed. Besides the two species of oyster, 

 the marine bands yield Panopcea plicata, Sow. (small), Serpulce, and 

 numei'ous fish-scales. The beds, being repeated on the shore by a 

 fault, afford great facilities for the collection of their fossils. The 

 Barnes series presents its usual sandy characters, and is about 

 50 feet thick. It contains several beds with plants and insects ; but 

 I did not here observe any marine bands in it. 



3. Sandown Bay. On the south-west side of this bay the Punfield 

 beds are quite concealed, forming low ground covered by vegeta- 

 tion ; but on the north-east side of the bay, below the Eed Cliff, the 

 strata in question are weU exposed. By a recent slip in the cliff 

 the junction of the Upper Neocomian and Wealden is well exposed 

 (1870), and yields the following section. 



* Quart. Journ. Geol. Soc. vol. xxvi. p. 3. 



t Memoirs of the Greological Survey, Geologv of the Isle of Wight, plate 2. 

 fig. 1. 



