265 



shells are sometimes found scattered among a multitude of 

 acknowledged sea shells, as oysters, venus's, &c. He, also, 

 in answer to M. Brongniart's having asserted that these 

 fossil shells " were alike in every respect to those which 

 we find in our marshes," declares that they differ decidedly ; 

 that there is not one of them whose living analogue is to be 

 found among the fresh-water shells of France ; and observes, 

 that buli mus pygmaus, whose fresh-water origin had been 

 assumed, agrees, in some respects, v/ith shells found in the 

 calcareous rocks of Mayence, and which had been supposed 

 to have been of fresh-water origin ; but the living analogues 

 of which Faujas St. Fond had found on the shores of the 

 French ocean and of the Mediterranean seas, as well as in 

 some of the salt-water marshes. M. Brard adds, that in 

 five places out of six where he had found the lymnece, &c. 

 they were imbedded in isolated blocks, which, he supposes, 

 had been broken up from the sides of the waters where 

 these animals had lived, and had been brought to these 

 places by a diluvial torrent.* 



On the other side, M. Brongniart, in proof of the agree- 

 ment of these fossil shells with the recent, states his having 

 found amongst them the cast of a cyclostoma elegans, and 

 mentions several of these shells which he thinks very nearly 

 agree with recent species. M. Brard having figured and 

 described a species of melajiia, inelanie effilee, as existing 

 among these fresh-water shells, M. Brongniart says, that he 

 discovered, by his own examination, what he should never 

 have found by M. Brard's description or figure, that this 

 sea shell was cyclostoma mumia, a land shell : and as to the 

 bullimi of Faujas St. Fond, both those which were found 

 fossil and recent, he was satisfied were also cyclostomce. 

 But, with respect to the cerithium mentioned by Brard, 



* Annales du Mus. Tom. xv. p. 36G. 

 M m. 



