PALEONTOLOGY. 141 



Cstrea Bellovacina among the green- coated flints at 

 the base. In the sands above we find only a few speci- 

 mens of Ostrea and Cyrena cordata, which are readily 

 separated from the matrix, but in a very friable condition, 

 so that careful handling and packing are required ; but 

 these afford sufficient evidence (in addition to that of 

 stratigraphical position) to identify the beds as belong- 

 ing to the Woolwich and Eeading group of the Eocene 

 series. 



An example of surveying among the older rocks is 

 also given in fig. 21, and our palseontological explora- 

 tions are here even more useful and necessary to con- 

 firm the conclusions drawn from the stratigraphical 

 evidence. 



In the sandstone quarry, No. 2, it will be noted 

 that some fragments of a substance resembling wood 

 were found ; these, when subsequently sliced and 

 subjected to a microscopic examination, show the cha- 

 racteristic structure of coniferous wood, but at the time 

 of collecting they could only be entered as " fragments 

 of wood, coniferous ?" In the shales forming the upper- 

 most part of the quarried cliff fish scales were noticed 

 to be tolerably abundant, and portions of the crushed 

 skeletons may also be detected, belonging to the Lepi- 

 dostean fish Palceoniscus comptus, which is characte- 

 ristic of the Permian marl-slate ; we are sure, therefore, 

 that the shales belong to this division of the series. 



In the limestone quarry to the south-west fossils are 

 much more abundant, though confined to the grey lime- 

 stone in the upper part of the quarry. Some parts of 

 this may not be accessible, but numerous blocks of it 

 are lying about, and we find that the fossils are readily 

 extracted from the rock ; at the same time they are 



