The burr-stone strata of the Southern States contain so many fossils agreeing with those of Claiborne, that it doubtless belongs to the same part of the Eocene group, though I was not fortunate enough to see the relations of the two deposits in a continuous section. Mr. Tuomey considers it as the lower portion of the series. It may, perhaps, be a form of the Claiborne beds in places where lime was wanting, and where silex, derived from the decomposition of felspar, predominated. It consists chiefly of slaty clays, quartzose sands, and loam, of a brick red colour, with layers of chert or burr-stone, used in some places for millstones. FOOTNOTES: [191-A] Leyde Magaz. voor Wetensch Konst en Lett., partie v. cahier i. p. 71. Cited by Rozet, Journ. de Geologie, tom. i. p. 43. [191-B] M. C. Prevost, Submersions Iteratives, &c. Note 23. [192-A] Cuvier, Oss. Foss., tom. iii. p. 255. [194-A] This species is found both in the Paris and London basins. [197-A] Coquilles caracterist. des Terrains, 1831. [197-B] Quarterly Geol. Journal, vol. iii. p. 353. [199-A] Prestwich, Quart. Geol. Journ. vol. iii. p. 386. [199-B] Palaeont. Soc. Monograph. Rept. pt. ii. p. 61. [202-A] For description of Eocene Cephalopoda, see Monograph by F. E. Edwards, Palaeontograph. Soc. 1849. [203-A] Annals of Nat. Hist. vol. iv. No. 23. Nov. 1839. [206-A] Murchison, Quart. Journ. of Geol. Soc. vol. v., and Lyell, vol. vi. 1850. Anniversary Address. [206-B] See paper by the author, Quart. Journ. Geol. Soc. vol. iv, p. 12.; and Second Visit to the U. S. vol. ii. p. 59. [206-C] Quart. Journ. Geol Soc. vol. vi. p. 32. [207-A] See Memoir by R. W. Gibbes, Journ. of Acad. Nat. Sci. Philad. vol. i. 1847. [208-A] Lyell, Quart. Journ. Geol. Soc. 1847, vol. iv. p. 15. CHAPTER XVII. CRETACEOUS GROUP. Divisions of the cretaceous series in North-Western Europe--Upper cretaceous strata--Maestricht beds--Chalk of Faxoe--White chalk--Characteristic fossils--Extinct cephalopoda--Sponges and corals of the chalk--Signs of open and deep sea--Wide area of white chalk--Its origin from corals and shells--Single pebbles in chalk--Siliceous sandstone in Germany contemporaneous with white chalk--Upper greensand and gault--Lower cretaceous strata--Atherfield section, Isle of Wight--Chalk of South of Europe--Hippurite limestone--Cretaceous Flora--Chalk of United States.