BQUITALENTS. 



9. Sparry limerock. > These afe all equivalent 



10. Calciferous sandrock. v to the European carbonif- 



11. Metalliferous limerock. \ erous or transition lime- 



stone ; as they immediately underlay the slate rock, con- 

 Different taining the greatest coal measures. In some localities 

 same^forma- ^^^7 Unite our lower cherti/ or cavernous limerock, which 

 *'on. rests upon the metalliferous limerock, as in Catskill, in 



N. Y. Though all these constitute the same calcareous 

 formation in this country, they present such well charac- 

 terized distinctions, and are so extensive, they ought not 

 to be united in the same stratum. 

 Lower 86- 12. Second graywacke. The slate is called limestone shale ; 



tondarj. 



i and the millstone grit and rubble are called the same. — 



I Psammite As this stratum is often confounded with the first gray- 

 true foreign wacke, by the English, the psammite of Brongniard, may 

 be given as its genuine equivalent. It is called slate clay 

 and coal grit, by De La Beche. 

 13. Saliferous rock. Salif erous sandstone and red marl, 

 variegated sandstone. 

 No equira- 14. Ferriferous ROCK. No equivalent has been observed in 

 ennn Eu- Europe, excepting in limited masses, which have not been 

 arranged among general strata. Its vast extent here de- 

 mands a place in the system. The lower part of the Eu- 

 ropean lias is sometimes red and grey, and highly ferru- 

 j ginous ; which may be a trace of this stratum. 



1 Water ce- 15. LiAS. Same. It is also found to be, in many places, the 

 I true water-setting lime and alum shale ; precisely like the 



Common European, It also contains pseudomorphous crystals, 

 fliltcryetali. imitating muriate of soda. 



jCherty 16. Geodiferous LIMEROCK. ") Upper carhoniferousMmQ' 



a^d swine- > _ . 



s^ne. 17. CoRNiTiFEROUS LIMEROCK. ) stone. Upper cherty lime- 

 stone. Swinestone. Perhaps this has no distinct equiv- 

 alent in Europe ; or it may be equivalent to the upper car- 

 boniferous, separated by the interposed underlaying rock. 

 It seems to agree pretty well with Buckland's description 



