182 



GEOLOGY OF THE ISLE OF WIGHT. 



Fig. 6C. 



Melanopsis 

 carinata^ Sow. 



!No section is visible, and the surface is imich obscured by waslied 

 gravel. The Bembridge Marls here consist of grey and white 

 clays with Cyrena. 



The fauna of the Bembridge Marls is not a prolific one. 

 Leaving out the mammals, which are little known, though 

 apparently the same as those of the Limestone, the vertebrates 

 are turtles, crocodiles, and fish, such as occur throughout the 

 Oligocene Beds. 



The assemblage of mollusca is poor, consisting of abundance of 

 individuals belonging to comparatively few 

 species, the common genera being Cyrena, 

 Melania, Mclmiopsis (Fig. 66), nnd J*((bidma. 

 However, though the species are few, the 

 shells are fine and remarkable for their 

 beautiful state of ])reservation. The species 

 of Cyrena often retain their colour-markings. 

 In the marine beds, fossils are not usually 

 well preserved, but this horizon is especially 

 worthy of careful examination, for any cor- 

 relation with other districts must be founded 

 mainly on the marine mollusca. Though 

 few species of these mollusca have yet been 

 obtained, it is important to note that a 

 considerable proportion of them is con- 

 fined to this horizon. Among these 

 are Area Wcbsteri (Fig. 60, p. 173), and 

 Ostrea vectcnsis (Fig. 67). 



Certain thin seams in the Bembridge 

 Marls contain only freshwater forms ; 

 but the usual character of the deposits 

 and their included fauna points to an 

 estuarine origin. Red-mottled lagoon 

 clays, with nothing but remains of 

 turtles and crocodiles, are compara- 

 tively rare in these beds, though they 

 appear again and again on diflTerent 

 horizons throughout the Oligocene and 

 Eocene formations. 



Drift-wood, seeds, and fruit are com- 

 mon in the Bembridge Marls, especially 

 near Hamstead and Yarmouth, but few 

 plants have yet been determined. The 

 only good^ leaf-bed yet observed seema 

 to be the insect-limestone, where, how- 

 ever, leaves are not abundant. 

 The following list of the Bembridge plants has been revised 



by Mr. Gardner; but the whole flora being under examination 



the list can only be regarded as provisional : — 



Fig. 67. 



Ostrea vectensis, 



Forbes. 



