51 
ed and approaching to conglomerate, from the roomviii. 
Hartz, where the metallic ores are principally n / t 7h7st, 
found in it. — Fletz (secondary^ rocks of this 
formation ; sandstone ; oldest sandstone with 
and without petrifactions ; old red and white 
sandstone, variegated sandstone, filtering stone ; 
sandstones of large grained concretions passing 
over into conglomerates, to which, in point 
of external appearance, may also be referred 
some kinds of breccia and puddingstone (the 
beautiful Breccia verde dEgitto composed 
principally of rounded pieces of a green 
horn stone, of granite, porphyry, &c. in a 
mass which is itself a fine grained pudding- 
stone).* As subordinate to the old sand- . 
stone formation are added some kinds of coal, 
together with specimens of slate clay (Fletz clay 
slate of some), generally forming the immediate 
roof of beds of coals; slate clay with the charac- 
teristic impressions of vegetables, from Ilmenau 
in Thuringia, where it alternates with coal and 
sandstone; from Planitz, &c. ; common clay iron 
stone, occurring in some coal formations, especial- 
N 2 ]y 
* The largest and most valuable monument now known to 
exist of this breccia is the Alexandrian Sarcophagus in the Gallery 
of antiquities of the Museum. 
