J42 OUR COMMON BRITISH FOSSILS. 



in the Chalk, and in the flints which come from that 

 deposit. In the Chalk quarries at Gravesend, Charlton, 

 many places in Kent and Sussex, as well as Norfolk 

 (particularly about Norwich), remains of these Echino- 

 derms may be found. I have seen perfect specimens 

 imbedded in the flint nodules obtained from Ipswich 

 and Norwich. All the Cretaceous star-fishes belong to 



Fig. 117.— Fossil Star-fish from the Rhaetic beds {Oj>htoleJ>is Daviesit), lower side. 



existing genera, such as Stellaster^ Goniaster, Orcaster, 

 etc. In the London Clay of the Isle of Sheppey we 

 find similar remains of Goniasters ; ossicles, plates, 

 etc., in a more or less perfectly preserved condition. 



We have already seen that, to a great extent, 

 Encrinites occupy the place in the rocks of the 

 Palaeozoic epoch subsequently held by Sea-urchins 

 and their allies in the Secondary strata, and in the 



