Gcological Sociefij of London. 
235 
opinion, there is perfeet conformity between the Mudstones and the 
underlying Coniston Limestone. They regard the G-raptolitic Mud- 
stones as constituting a definite geological horizon of more than 
local importance, as they have been recoguized in Ireland, Sweden, 
Carinthia, and Bohemia. 
The Graptolitic Mudstones are succeeded by the “ Knock beds,” 
so called from their great development in Swindale Beck, near 
Knock. Wherever they occur, they oonsist chiefly of pale-green, 
fine-grained slates, very ashy in appearance, and presenting many 
dendrites, and frequently crystals of cubic pyrites. There is no 
evidence of unconformity between them and the underlying Mud- 
stones. The former contain scarcely auy fossils. They are directly 
surmounted by the “Coniston Flags,” representiug the Denbighshire 
Flags of North Wales, which have been shown to be of Upper 
Silurian age. Hence the authors conclude that the Knock beds 
must be either the basement series of the Upper, or the summit 
series of the Lower Silurian, or eise a group of passage-beds between 
the two. The palseontological evidence is insutficient to settle the 
point, but it tends to show that the Knock beds are at the base of 
the Upper Silurian, an opinion which is oorroborated by their 
lithologieal resemblance to the Tarannon slates of Wales. 
The paper concluded with an appendix on the Irish rocks referred 
to above. 
2. “ On a new Area of Upper Cambrian Kocks in South Shrop- 
shire, with the Description of a new Fauna.” By C. Callaway, Esq., 
M.A., F.G.S. 
The purpose of the author was to prove that certain olive, mica- 
ceous, thin-bedded shales exposed at Shineton, near Cressage, and 
covering an area of eight miles in length by two in the greatest 
breadth, which had been mapped as Caradoc in the survey, were of 
Tremadoc age. They were seen clearly to underlie the Hoar Edge 
Grit, the lowest beds in the district, with Caradoc fossils ; and no 
rock distinctly underlying the shales could be detected. The evi- 
dence for their age was chiefly palaeontological. With the exception 
of Asaplius Homfrayi, a Tremadoc form, the species are new. 
Genera such as Olenus, Conocoryphe, Obolella, and Lingulella, 
suggested a very low horizon, but two Asaphoid forms (tliough not 
typical AsapJii ) pointed in an opposite direction. Corroborative 
evidence was found in a correlation of the shales at Shineton with 
the Dictyonema-shales at Pedwardine and Malvem. It was shown 
from lithologieal characters and from fossils that the shales at the 
three localities were of the same age ; and as the beds at Pedwar- 
dine and Malvem were, on their own testimony, admitted to be of 
Lingula-ä. ag or Tremadoc age, the Shineton shales were inferred to 
be on the same horizon, the Asaphids leading the author to adopt 
the younger of the two formations. He was of opinion that the 
Black Shales of Malvern (Dolgelly beds) were not represented in 
the Shineton area. He announced the discovery of the Hollybush 
Sandstone, forming a continuous band between the Shineton Shales 
and the Wrekin axis, recoguized by the occurrence of Eutorgina 
