It is true that this bank of shells appears to be exactly correspondent 

 with that which exists in Hampshire, the fossils of which have been so 

 well illustrated by the labours of Brander and Solander. But, whilst 

 the Hampshire fossils are generally broken, from the very soft and fragile 

 state to which they are reduced by the mud in which they are involved, 

 the fossil shells of France are found in the highest state of preservation : 

 and hence numerous species, which can in this island be hardly ever 

 obtained, are there found in a perfect state. How assiduously and suc- 

 cessfully M. Lamarck has employed these several advantages, will be 

 manifested by the arrangement he has formed, and the important obser- 

 vations which he has made. 



Of the testaceous molluscae he considers the cephalous, from being 

 the most perfect, as being proper to form the first order. With the 

 exception of the chiton, all the other cephalous conchyliferus molluscae, 

 he observes, are simply univalves, whilst the acephalous are inclosed in 

 two or more valves. 



Genus I. Chiton. An oblong-elliptical, convex, multivalved shell ; with 

 transverse valves, partly lying over each other, in a row, on the back 

 of the animal. 



The only notice which I find taken of the fossil remains of this ani- 

 mal is by Lamarck, who states, that the separated valves only are found 

 at Grignon. From this separation of the valves he finds it difficult to 

 determine to what species these fossil remains belong, but conjectures 

 that it is to C. octovalvis. I am happy in possessing a very perfect spe- 

 cimen of the fossil testaceous covering of this animal from Grignon, and 

 in its confirming the opinion of M. Lamarck, as to the number of its 

 valves, which are eight. 



This fossil is in so high a degree of perfection, as to have made me at 

 one time suspect its being only decomposed by exposure to the air ; but, 

 an examination with a lens, showed not only the adherent matrix, but 

 two species of extremely minute fossil serpulae fixed on its convex surface. 



VOL. III. H 



