BEMBRIDGE MARLS. 



175 



f Green clay, weathered in the upper part. 

 I Melania turritissima in pyrites - 

 I Seam of marl with Melania muricata, 

 Bembridge Marls -^ Melanopsis and Hydrobia Chasteli. 



Green clay . . . - 



Line of ironstone nodules. 



Green clay (2| feet seen) - dug for 



Ft. In. 



3 



1 



12 6 



24 5 



Fig. 61. 



Hydrobia 



Chasteli, Nyst. 



The occurrence of a thin shelly seam full of 

 Hydrobia Chasteli three feet below the Black 

 Band is noticeable. This Hydrobia was formerly 

 considered to be characteristic of the Hamstead 

 Beds, but now we find that wherever there is a 

 clear section of the upper part of the Bembridge 

 Marls this thin seam — never more than two inches 

 thick — is found at from three to eight feet below 

 the Black Band. It is well seen on the foreshore at Hamstead 

 and near Yarmouth. 



On the east bank of the Medina, near Whipphigham, one of 

 the trial-borings made by the Survey reached clay full of Serpula, 

 apparently belonging to the lower part of the Bembridge Marls. 



Crossing the Medina good sections were exposed in the Zerena 

 shp-way, near Shambler's Copse. At the time of the re-survey 

 the section was obscured, but it appears to have cut through the 

 marine beds and the underlying Limestone. The following fossils 

 were found in the spoil heap : — 



Cyrena obovata. 

 ,, obtusa. 



„ semistriata. 

 Cerithium elegans. 



Cerithium mutabile, 

 Melania muricata. 

 Melanopsis carinata. 

 Lamna (tooth). 



Fig. 62. 



Pseudocythere 



Bristoviij Jones 



& Sherborn.* 



Similar beds were well seen in a deep ditch by the side of the 

 railway cutting a quarter of a mile further south, close to Bolton 

 Copse. Here the base of the Marl is crowded 

 with Melania muricata, so that the heaps 

 looked quite white after rain. The other 

 species obtained were Serpida tenuis, Cyrena 

 obovata, C. obtusa and Cerithium mutabile. 

 In places, a seam of white marl hardens into 

 a shell- limestone containing Cyrena semis- 

 triata, Cerithium mutabile, and Neritina 

 concava. In this Cyrena limestone J. Rhodes 

 found a new Cyprid (Fig. 62). 



A mile further south, at Werror Brick 

 Yard, J. Rhodes obtained Plant-remains, 

 Fish-bones, Faleryx, and a phalanx of a Bird. 

 These were found immediately below the 

 Hamstead Beds, which are also shown in the 

 same pit. At this point the Bembridge Marls 

 are lost beneath the marsh level. 



A series of wells at Cowes, the West 



. Right valve (slightly 

 broken along the ven- 

 tral edge). 



Edge view. Magni- 

 fied 20 diam. 



* Supp. Monogr. Tert. Entom. Fal. Soc, 1889. 



