dls, ON THE ANCIENT GRAUWACKE 
factions has been denied, and our author has been challenged 
to produce a single petrifaction in the Grauwacke of Dum- 
friesshire. To us, who know perfectly well that vegetable 
petrifactions are very common in that Grauwacke, this chal- 
lenge appears not a little bold.” Thus far the reviewer. He 
seems to have observed for himself, but not very correctly. 
Mr. Harkness tells us, in a paper which appeared in the 
“ Geological Journal” for 1851, that though the Dumfries 
Grauwackes contain’ their thick bands of anthracite, of ap- 
parently vegetable origin, there has been detected in them 
no vegetable remains whatever. They abound, however, in 
graptolites ; and it was probably these leaf-like zoophytes, 
whose nature is still so imperfectly understood, that caught 
the eye of the reviewer, and constituted his “ vegetable petri- 
factions.” The Grauwacke of Scotland does, however, con- 
tain vegetable impressions apparently fucoidal ; though they 
are far from common in any of the rocks which I have yet 
seen, and yield no characters by which they can be distin- 
guished from the simpler fuccids of the Old Red Sandstone. 
In one of the specimens now on the Society’s table, derived 
from the shales of Girvan, there occurs a fucoidal stem of this 
latter description, associated with graptolites of the double- 
sided genus diprion,—a genus never found, it is said, save 
in the Lower Silurian. 
In 1808, Professor Jameson published that third volume 
of his “System of Mineralogy, in which he fully developed 
his geological views, and described in language that has since 
become obsolete, the character and order of succession of the 
various formations. The work, however, added nothing to 
the previous knowledge of our Scotch Grauwacke, save per- 
haps, a very curious hypothesis regarding its convoluted 
strata, framed evidently to meet the theories of Hutton and 
Sir James Hall. “Very striking curvatures sometimes oe- 
