326 Mr. Parkinson on the Strata, 



the uppermost strata : that some fossils, occurring in considerable 

 numbers in one stratum, become very rare in the adjacent portion of 

 ,the next superincumbent stratum, and afterwards are lost : that fossils 

 of one particular genus, which exist abunTlantly in tl^e lower strata, 

 and occur in several of the superincumbent ones, are not found in 

 the three highest strata ; whilst one species of that genus, but which 

 has not been found in a fossil state, exists in our present seas : and 

 lastly, that most of the remains which are abundant in the superior 

 strata, are not at all found in the lower. These general facts lead us 

 to hop€, that geology may derive considerable assistance, from an ex- 

 amination of fossils, made in connexion with that of the strata to 

 which they belong. 



The following is an attempt to investigate on this plan some of the 

 upper strata in the vicinity of the metropolis with their contained 

 fossils ; and, although by no means complete, it will, it is hoped,induce 

 'Others, who possess superior abilities and opportunities, not only to 

 re-examine more correctly tliese strata, but to extend tlieir researches 

 to the subjacent strata. 



The whole of this island displays evident marks of its stratification 

 having, since its completion, suffered considerable disturbance, from 

 some prodigious and mysterious power. By this power all the 

 known strata, to the greatest depths that have been explored, have 

 lieen more or less broken and displaced ; and in some parts have 

 been so lifted, that some of the lowest of these have been raised to 

 the surface ; whilst portions of others, to a very considerable depth 

 and extent, have been entirely carried away.* From these circum- 



* See several essays on this suhjcct in the Phllosephical Magazine, b^ .'Jr. Farcy, and 

 the llcport on Derbyshire, vol. I. p. 105. 



Also a Letter on theaUcrations Mfhich have taken plare in the iimcturc of rorks, on 

 the surface of the basaltic couulry in tlie counties of D.ivj ami Antrim, !)y William 

 Ilichardbon, D.D. Pliil. Trans. 1808. 



