132 BRITISH FOSSIL REPTILES. 



my esteemed friend, by whose scientific and zealous investigations so much valuable 

 additional knowledge has been obtained respecting the fossils of that rich, but, previously 

 to his researches, little known locality. 



The tooth represented of the natural size in fig. 10, PI. 3 B, was also discovered at 

 Bracklesham, and forms part of the collection of G. Coombe, Esq. It resembles, in its 

 proportions and obtuse extremity, the teeth of the Crocodiles rather than those of the 

 Gavials, and at first sight reminded me of those of the GoniopIioUs or araphicoelian 

 Crocodile of the Wealden period. On comparing it closely ■«ith similar-sized teeth of 

 that species, the enamel ridges were more numerous and decided in the Goniopholii ; 

 and the delicate reticular surface in the interspaces of the more widely separated and 

 feebler longitudinal ridges in the Bracklesham tooth was wanting in the GonioplioUs. 

 The minute superficial characters of the enamel of the large and strong Crocodilian 

 tooth from Bracklesham, closely agree with those of the Gavialis Dixoni. It is just 

 possible that this may be a posterior tooth of a very large individual of that Gavial, as 

 the teeth become at that part of the jaw shorter in proportion to their thickness in the 

 modern Gavials. If it should not belong to that Gavial, it must be referred to a 

 Crocodile distinct from those species of the secondary strata, or those existing Crocodiles 

 which have teeth of a similar form ; since they present a different superficial pattern of 

 markings on the enamel. 



On reviewing the information which we have derived from the study of the fossil 

 remains of the procoelian Crocodilia, that have been discovered in the Eocene deposits 

 of England, the great degree of climatal and geographical change, which this part of 

 Europe must have undergone since the period when every known generic form of that 

 group of reptiles flourished here, must be forcibly impressed upon the mind. 



At the present day the conditions of earth, air, water, and warmth, which are 

 indispensable to the existence and propagation of these most gigantic of living Saurians, 

 concur only in the tropical or warmer temperate latitudes of the globe. Crocodiles, 

 Gavials, and Alligators now require, in order to put forth in full vigour the powers of 

 their cold-blooded constitution, the stimulus of a large amount of solar heat, with ample 

 vero-e of watery space for the evolutions which they practise in the capture and disposal 

 of their prey. Marshes with lakes, e "tensive estuaries, large rivers, such as the Gambia 

 and Niger that traverse the pestilential tracts of Africa, or those that inundate the 

 country through which they run, either periodically, as the Nile for example, or with 

 less regularity, like the Ganges ; or which bear a broader current of tepid water along 

 boundless forests and savannahs, like those ploughed in ever-varying channels by the 

 force of the mighty Amazon or Oronooko ; — such form the theatres of the destructive 

 existence of the carnivorous and predacious Crocodilian reptiles. And what, then, 

 must have been the extent and configuration of the eocene continent which was drained 

 by the rivers that deposited the masses of clay and sand, accumulated in some parts of 



