418 CLAY FAMILY. These colours are generally arranged in broad stripes, and often in veined delineations. It occurs massive. The fracture is coarse earthy, inclining to slaty. It is dull, both externally and internally. It becomes strongly resinous in the streak. The other characters as in the preceding subspecies. Geognostic and Geographic Situations. It occurs in alluvial deposites near Wehrau, in Upp# Lusatia. Observations. It is closely allied to Lithomarge, and even passes in- to it. Fourth Subspecies. Slate-Clay. Schiefer Thon, Werner. % Slate-clay, Shale, Kirman, vol. i. p. 182.—L’Argilc schisteu* 6 ' Brock, t. i. p. 327. Id. Ilauy, t. iv. p. 446.—Schiefer Tho”' Reuss, b. ii. s. 99- Id. Lud. b. i. s. 107. Id. Suck. l r s. 490. Id. Bert. s. 211. Id. Mohs, b. i. s. 440. Id. s. 47. Id. Leonhard, Tabel. s. 22.—Argile feuilletee, I> r ° n ^' t. i. p. 525. ?—Schiefriger Thon, Karsten, Tabel. s. 28^ Schiefer Thon, Steffens, b. i. s. 201. Id. Lcnz, b. ii. s. 55^' External Characters. Its colours are smoke and ash grey, greyish-bla^’ and sometimes brownish-red.
