392 
ELEMENTS OF GEOLOGY. 
The formation was well studied by the miners of that coun¬ 
try a century ago as containing a thin band of dark-colored 
cupriferous shale, characterized at Mansfield in Thuringia by 
numerous fossil fish. Beneath some variegated sandstones 
(not belonging to the Trias, though often confounded with it) 
they came down first upon a dolomitic limestone correspond¬ 
ing to the upper part of our Middle Permian, and then upon 
a marl-slate richly impregnated with copper pyrites, and con¬ 
taining fish and reptiles (Protorosaurus) identical in species 
with those of the corresponding marl-slate of Durham. To 
the limestone they gave the name of Zechstein, and to the 
marl-slate that of Mergel-schiefer or Kupfer-schiefer. Be¬ 
neath the fossiliferous group lies the Rothliegendes or Roth- 
todt-liegendes, meaning the red-lyer or red-dead-lyer, so called 
by the German miners from its color, and because the cop¬ 
per had died out when they reached this underlying non- 
metalliferous member of the series. This red under-Iyer is, 
in fact, a great deposit of red sandstone, breccia, and con¬ 
glomerate with associated porphyry, basalt, and amygdaloid. 
According to Sir R. Murchison, the Permian rocks are com¬ 
posed, in Russia, of white limestone, with gypsum and white 
salt; and of red and green grits, occasionally with copper 
ore; also magnesian limestones, marlstones, and conglolftier- 
atcs. 
Permian Flora. — About 18 or 20 species of plants are 
known in the Permian rocks of England. -IN'one of them pass 
Fig. 426. 
down into the Carboniferous series, but several genera, such 
as Alethopteris^ Neuropteris^ Walchia., and Ullmania^ are com¬ 
mon to the two groups. The Permian flora on the Continent 
appears, from the researches of MM. Murchison and de Ver- 
