STRATA OF TILGATE FOREST. 49 



iron ; and when exposed to the action of the blow-pipe, evince unequivocal 

 proofs of their animal origin. Their cellular structure is sometimes 

 beautifully displayed, being injected either with limestone, or crystallized 

 carbonate of lime ; and in numerous specimens the medullary cavities of 

 the long bones are filled with white semi-transparent calcareous spar. 

 The vertebrae are the most entire, but even these have their bodies more 

 or less compressed, and their processes broken, or altogether destroyed. 

 But notwithstanding the mutilation these remains have undergone, their 

 osteological characters are stiU sufficiently marked, to denote not only the 

 genus of the animal to which they belonged, but also to afford some slight 

 indication of its species. 



The following are the most illustrative specimens in my possession, 

 and from which the suggestions hereafter offered concerning the nature of 

 the original, are principally derived. 



24. Teeth of a conical form, slightly curved, their surface covered with 

 numerous longitudinal ridges or striae, which converge towards the apex : 

 the superior terminations are acuminated in some examples, and rounded 

 or obtuse in others. 



These fossils are either round, or somewhat compressed, and vary 

 considerably in size and curvature; they are from 0*2 inch to S inches 

 long, and from OS inch to 2*8 inches in circumference at the base ; 

 the upper part only is striated, the lowermost half being perfectly 

 smooth. AVith but few exceptions they consist of the crown of the 

 tooth only, appearing as if broken off close to the jaw; and although in a 

 few instances part of the fang remains, yet the detached state in which 

 they are found, prevents their mode of insertion from being accurately 

 determined. The fangs are hollow like those of the crocodile, but the 

 presence of younger teeth within the cavities of the older ones, as in that 

 animal, has not been detected *. 



The teeth possessing the characters here enumerated, constitute the 

 following varieties, but whether they originally occupied different situations 



* In a specimen recently discovered, this structure is however very apparent. 



H 



