454 OLIGOCENE. 



BEMBRIDGE BEDS. 



This series, named by Prof. Forbes from Bembridge, south-east 

 of Ryde, has been subdivided as follows : — 



(Upper Bembridge Marl, consisting of marls and laminated grey clays, 

 yielding in great abundance Rlehuiia ticrritissinia. 

 Lo'cver Bembridge Marl, comprising unfossiliferous mottled clays 

 alternating with fossiliferous laminated clays and marls, with 

 Cerithiimi tnutabile, Cyreiia piilchra, etc. 

 Bembridge Oyster Bed, a band containing Ostrea Vedensis. 

 Bembridge Limestone, comprising the uppermost shell-limestones (25 

 feet) of Headon Hill, Sconce, Hempstead Ledge, Gurnet Bay, 

 near Cowes, Binsted, Bembridge, etc. This limestone is some- 

 times hard and compact, at others soft and tufaceous ; it is 

 cream-coloured, and occurs in layers from i to 6 feet thick, with 

 clays and marls, attaining a total thickness of 25 feet. The beds 

 contain Claitsilia, Biilimus ellipticus (Bulimus limestone). Helix 

 globosa, Platiorbis discus, and Limn tea longiscata (Limn^an 

 limestone). 



The Bembridge Marls attain a thickness of about 90 feet, and 

 are well seen below St. Helen's, by Brading Harbour, at White- 

 cliff Bay, and at Hempstead ; and they occur at Osborne. The 

 Oyster-bed, consisting of green sand and shelly marl, about 18 inches 

 thick, is shown in Whitecliff Bay, and near St. Helen's by the 

 entrance to Brading Harbour. In addition to the fossils already 

 mentioned, the Bembridge Beds have yielded remains of T?ionyx', 

 also the Mammalia Anoplotherinm, Cfice?'opo/amus, Pterodon, Dicho- 

 bune and Palccolhcrium;'^ the Phyllopod Brajichipodites Vectc7isis •,'^ 

 and some Plant- and Insect-remains obtained by Mr. J. A'Court 

 Smith from the Bembridge Beds of Gurnet Bay.^ 



The Bembridge limestone has been largely quarried at Binsted (near Ryde), 

 East Cowes, etc. ; Quar Abbey, Yarmouth Castle, and portions of the interior 

 of Winchester Cathedral were constructed from it, but the beds are now seldom 

 worked. 



HEMPSTEAD BEDS. 



These beds, named by Prof. Forbes from their occurrence at 

 Hempstead between Yarmouth and Cowes, have been divided 

 as follows : — 



Ft. ins. 

 Corbula Beds. Brown and greenish clay with shelly bands, Corbula 



pisiim, C. Vectensis, etc 15 O 



/ Upper, containing Cerithiumplicatiu)!, C. elegans, Corbula, 



Freshwater^ Bissoa, Hydrobia, Melauia, Pahuii)ta, etc 40 O 



and 5 Middle, with Cyrena semistriata, Cerithiiim, Rissoa, 



Estuarine \ Panoptra minor, etc 5° *^ 



Marls. \ Lower, with Melania muricata, M. fasciata, Melanopsis 



\ carinata, Cyclas Brisiovii, Unio Gibbsii, etc 65 o 



» S. P. Pratt, T. G. S. {2), iii. 451. ^ jj^. H. Woodward, Q. J. xxxv. 346. 



^ J. S. Gardner, P. Geol. Assoc, vi. 91, viii. 312 ; Rep. Brit. Assoc. 1S86. 



