q 
o4 CO. Lapworth—Recent Discoveries in Sweden. 
by Orthis argentea, His., and an undetermined species of Climaco- 
graptus. 
T will not follow the author into the discussion of the relationship 
of this last zone to the Chasmops and Trinucleus Shales, but will stay 
for a moment to glance at his attempt to parallel these Graptolitic 
Zones with their extra-Swedish representatives, 
He does not definitively assign the (a.) Phyllograptus Zone either 
to the Arenig or Llandeilo. That question cannot, indeed, be satis- 
factorily settled until we know more of the Graptolites of the Lower 
landeilo and Upper Arenig. 
(b.) The Geminus or Murchisont Zone he rightly assigns most em- 
phatically to the Lower Llandeilo, from the abundance of its 
characteristic fossil, which also occurs in millions in the Lower 
Llandeilo of South Wales. 
The next three zones he parallels confidently with the Scotch 
Glenkiln Shales, or Lower Moffat. At the time his paper was 
published, this comparison was inevitable; but my studies of the 
Graptolite-bearing Llandeilo rocks of South Wales lead me to 
suspect that my Glenkiln Shales embrace only the higher zones of 
the beds that actually lie between the Ogygia-bearing, or so-called 
Middle Llandeilo, and the representatives of the Hartfell Shales; 
and I am at present inclined to the opinion that his zone (e) of 
Climacograptus Scharenbergi actually represents the whole of the 
Glenkiln Shales, the zones (c) and (d) not having yet been recog- 
nized in the South of Scotland. 
His reference of the succeeding Dicranograptus Clingani and 
Orthis argentea zones to the general horizon of the Hartfell Shales 
of the South of Scotland, is, and will always probably remain, un- 
assailable. If, however, they actually antedate the Trinucleus 
Shales of other districts of Sweden, they can only admit of com- 
parison with the Lower Hartfell. 
It is at present a matter of impossibility to parallel these Swedish 
beds with the three supposed Welsh formations of the Arenig, 
Llandeilo and Bala. The Lower Graptolite Schists and the Ortho- 
ceras Limestone are distinctly of Arenig age. The Murchisoni Bed 
of the Middle Graptolite Schist cannot yet be assigned either to the 
Arenig or the Llandeilo. Zones 6, c, and d, I believe to be Llandeilo, 
while the last three zones are probably wholly of Bala age. 
Upper Graptolite Schists (Monograptus Schists).—The final member 
of the Ordovian or Lower Silurian system of Sweden is the Trinu- 
cleus Schist, which, though the two have never actually been found 
in physical juxtaposition, probably overlies the argentea zone. The 
first member of the Silurian proper is the Brachiopod Schist, from 
which Graptolites are wholly absent. This is followed by a mass 
of Graptolitic Shales, dark and finely laminated at the base, but 
becoming lighter in colour and occasionally of coarser character 
higher up. The lower beds as exposed in Westrogothia, etc., have 
been denominated by Tornquist the “ Lobiferus Schists.”” Wherever 
they occur in Scania they can be immediately recognized both by 
their marked mineral character and by their fossils. From these 
beds Linnarsson and Schmalensee have procured Rastrites peregrinus, 
