352 PETRIFACTIONS AND THEIR TEACHINGS. CHAP. III. 



gate Forest." l Several teeth, and specimens of the median 

 bones of the sterno-costal arcs, and portions of coracoids of 

 plesiosauri, have also been found in other localities. These 

 remains were in the same fragmentary and waterworn con- 

 dition as those of the terrestrial reptiles. 



The occurrence of the bones of this remarkable type of 

 marine saurians in the freshwater formation of the south-east 

 of England, may be attributable to the influx of the tidal 

 waters into the ancient estuaries and bays ; but it is also 

 probable, from the presumed habits of the Plesiosauri, that 

 the embouchure of the river of the Country of the Iguanodon 

 was frequented by shoals of these reptiles, as well as by 

 turtles and predatory fishes. Unfortunately, the bones of 

 Plesiosauri collected by me, and transferred to the British 

 Museum in 1839, are not yet placed so that they can be 

 referred to in this volume ; but the fact is worthy of record 

 in relation to the history of the Wealden formation. 



%* In consequence of the arrangement of the fossils in 

 this room, we must defer the consideration of the other group 

 of Enaliosaurians, the Ichthyosauri, till the next chapter, and 

 proceed to notice the contents of Wall-case G, which chiefly 

 consist of an interesting series of mammalian and other 

 remains, from the tertiary deposits of Central France. (See 

 ante, p. 143.) 



1 1 Vol. 4 to. Published in 1827, PI. IX. figs. 4, 5 ; PI. XVII. fig. 20, 

 p. 79. 



