36 



cretionary and amorphous portions of the same matter dispersed 

 throughout the sandstone of this bed, were masses of the fossihzed 

 bodies of the animals which had become disengaged from their shells, 

 and had floated in the sea till envelope^ in the sand and mud, which 

 is now concreted to the coarse sandstone called Kentish Rag. In 

 proof of this opinion reference is made to an account published in 

 the ' American Journal of Science' for 1837, of the efi^ectsof an epi- 

 demic among the shell-fish of the Ohio, which, killing the animals, 

 their decomposed bodies rose to the surface of the water, leaving the 

 shells in the bed of the stream, and floating away covered the banks 

 of the river. Mr. Bensted points out that nearly the whole of the 

 shells in the Kentish rag of his quarry appear to have been dead 

 shells, and infers that their death might have been owing to a similar 

 cause with that which destroyed the Uniones in America ; while their 

 bodies intermingling with the drift wood on a sand-bank furnished 

 the concretions described in this communication. 



The Rev. J. B. Reade submitted some of the substance of these 

 bodies to an analysis by Mr. Rigg, who confirmed Dr. Mantell's 

 suspicion of the presence of animal carbon in it, and states that the 

 darker portion of the substance contains about 35 per cent, of its 

 weight of carbon in an organized state. 



Dr. Mantell adds, that a microscopical examination with a low 

 power detects innumerable portions of the periosteum and nacreous 

 laminae of the shells of extreme thinness intermingled with the car- 

 bonaceous matter, together with numerous siliceous spiculse of 

 sponges, very minute spines of Echinodermata, and fragments of 

 Polyparia, and remarks that these extraneous bodies probably became 

 intermingled among the soft animal mass before the latter had un- 

 dergone decomposition. He proposes to term the substance Mol- 

 luskite, and states that it constitutes the dark spots and markings in 

 the Sussex and Purbeck marbles. 



" On the Geological position of the Mastodon giganteum and as- 

 sociated fossil remains at Bigbone Lick, Kentucky, and other local- 

 ities in the United States and Canada." By Charles Lyell, Esq., 

 V.P.G.S. 



With a view to ascertain the relations of the soil in which the 

 bones of the Mastodon are found, to the drift or boulder formation, 

 whether any important geographical or geological changes had 

 taken place since they were imbedded, and what species of shells are 

 associated with them, Mr. Lyell visited a number of places where 

 they had been obtained. In this paper he gives the result of his 

 researches. 



The most celebrated locality visited was Bigbone Lick, in the 

 northei'n part of Kentucky, distant about 25 miles to the S.W. of 

 Cincinnati, situated on a small tributary of the river Ohio called 

 Bigbone Creek, which winds for about 7 miles below the Lick before 

 joining the Ohio. A "Lick" is a place where saline springs break 

 out, generally among marshes and bogs, to which deer, buftaloes, and 

 other wild animals resort to drink the brackish water and lick the salt 



