309 



all connected with the amount of silex, but depended upon 

 some other laws into which they had at present no insight. 

 He described a portion of a jaw of a fossil reptile, ( the 

 Mosasaurus Stenodon,) which had been found in a chalk 

 pit on the banks of the Thames, in 1835, and which had 

 been found to contain something which greatly surprised 

 him. He had the specimen placed in the hands of a 

 lapidary, with instructions that he should saw him one of 

 the teeth. When the instrument came to the middle of 

 the tooth, something very hard arrested its further pro- 

 gress. The tooth was accordingly broken ; and, on its 

 falling in pieces, there was exhibited this remarkable 

 feature, that in the very centre of the tooth was a piece 

 of solid black flint, filling that portion of the pulp-cavity 

 bounded by the expanded base of the tooth, as well as 

 the extension of this cavity into the jaw ; but there was 

 no silicification of the investing bone, and no ostensible 

 means of explaining the presence of the flint within the 

 tooth, but on the hypothesis of its precipitation from a 

 fluid, or of its having, in a viscid state, traversed the 

 passage connecting the pulp-cavity with the great medul- 

 lary canal of the jaw.* 



The Kev. Dr. Scoresby made a few observations on 

 the excellence of the papers which had been read, and the 

 importance of such meetings as the present. 



The Noble Chairman addressed the meeting as follows : 

 Ladies and Gentlemen, — We have listened to some observa- 

 tions respecting some remarkable phenomena ; but, although 

 we may indulge in high aspirations upon the subjects which 

 have been brought before us, and in the hope of further 

 discoveries following upon the patient investigation of facts, 



* Mr. Charlesworth has given a full account of this specimen and the above 

 interesting discovery, with figures, in the London Geological Journal, No. I., pp. 

 23 — 32, which lessens the regret we should otherwise feel in not being able to 

 give this communication entire. 



