Mantellian Museum at Lets^es, 1 1 



extraordinaire que tons ceux dont nous avons connoissance) , 

 It is indeed extraordinary not only from being the largest 

 amphibious or terrestrial animal hitherto known, but from its 

 peculiar structure as an herbivorous masticating reptile. These 

 preliminary observations are chiefly made, to prove to your 

 country readers, how much may be done for the promotion of 

 science, even in situations not favourable to its pursuit, at a 

 distance from public museums, and removed from the excite- 

 ment produced by associating with others engaged in kindred 

 studies. 



I now proceed to describe the museum. The room in 

 which the objects are placed has been recently erected by 

 Mr. Mantell for the purpose, and is well lighted from above ; 

 the larger specimens are arranged in glass cases, and the 

 smaller ones in drawers below. It has already been stated 

 that the collection of chalk fossils is the finest in the kingdom; 

 it will not be necessary to particularise them, except those 

 which are extremely rare, but it may be observed, that the 

 matrix in which the most delicate animal remains are embedded 

 has been partly removed with a degree of science and care 

 that I have noticed in no other museum, and they are dis- 

 played to the greatest advantage. The beautiful series of 

 fishes allied to the Sens or doree, from the chalk pits near 

 Lewes, are particularly interesting : one of them is a matchless 

 specimen, the mouth being open and entire, and the tongue 

 exposed ; but the most remarkable circumstance is the un- 

 compressed and perfect form of the bodies, which was doubt- 

 less chiefly owing to the preservation of the air bladder, for it 

 appears unbroken in many of these specimens. This is an 

 important fact, as it proves that the bodies were completely 

 incased in the chalk, before the putrefactive process had com- 

 menced, and adds probability to an opinion I advanced in a 

 former edition of my Introduction to Geology ; that the form- 

 ation of many beds in the secondary strata was effected by sub- 

 marine eruptions of hot water, saturated with earthy matter, 

 which destroyed the animals previously existing, and formed 

 around them a siliceous or calcareous' incrustation, that pro- 

 tected their remains from destruction. * 



In some of the fossil fishes, the dorsal fins, gills, and teeth 

 are preserved, as well as the air bladder and tongue ; the 

 scales are also very distinct. There are many fine specimens 

 of Ventriculites, first described by Mr. Mantell in the 11th 



* M. Alex. Brongniart to whom I sent a copy of that work has recently 

 adopted a similar theory to what I had advanced in 1815, that some of the 

 siliceous strata in the Paris basin were deposited by thermal waters holding 

 siliceous earth in solution. 



