642 PROF. W. BOYD DAWKINS ON [Nov. 1902. 
rocks, it is decided by the examination of the fossiliferous pebbles of 
both the Lower and the Upper Brockrams. The species which I 
have identified, by the kind assistance of Mr. E. T. Newton, F.R.S.,. 
and Mr. Rhodes, in the Museum of Practical Geology, Jermyn Street, 
are Griffithides glaber and Chonetes Lagquessiana, from the Lower 
Brockram of Peel. The latter occurs also in the Upper Brockram of 
the Stack Series, at Lhooby Reeast. Both are Carboniferous species. 
For the identification of a second series of species, of Ordovician 
age, I am indebted to Mr. Leonard Gill and Mr. F. R. Cowper 
Reed, M.A., F.G.S. They consist of Plectambonites quinquecostata, 
Platyceras verisimile, and Iilenus brevicapitatus (a variety of J. Bow- 
manr). These have been compared by Mr. Reed with the specimens 
in the Woodwardian Museum at Cambridge; and he identifies 
the limestone in which they occur with the Keisley Limestone, a 
rock restricted to one small inlier near Appleby. It is therefore 
obvious that the cliffs from which the Brockrams were torn were 
composed of Keisley Limestone, as well as rocks of Carboniferous 
age in the region of the Isle of Man, and that the Brockrams 
are, on the whole evidence, post-Carboniferous. 
The detailed account of the fossils of the Keisley Limestone in the 
Manx Brockrams must be reserved for a future paper. It is 
sufficient to note here that it has contributed largely to the pebbles 
in the Upper Brockrams at Whitestrand, while it has not as yet 
been identified in the Lower or Peel Series. 
A comparison of the rocks under discussion with the Permian 
of Barrowmouth near Maryport, and of the Vale of Eden near 
Appleby and Kirkby Stephen, so well described by Sedgwick, 
Binney, Eccles, Harkness, Nicholson, and others, proves that the 
sequence is of the same general order. The section at Barrowmouth 
shows about 5 feet of Brockram resting, unconformably, upon the 
waterworn surface, and passing into a Magnesian Limestone about 
8 feet thick. In the Vale of Eden the Penrith Sandstones, some 
2000 feet thick, contain Brockrams mainly massed in the lower and 
upper divisions, as is the case with the Peel Sandstones and Stack 
Conglomerates. They are chiefly composed of materials derived 
from the break-up of the Carboniterous rocks. The hematites, 
cherts, chalcedonies, and pebbles of Carboniterous Limestone and 
Yoredale rocks are the same in the Brockrams of both these districts. 
In Hilton Beck, the Penrith Sandstones dip under a series of marls 
and sandstones, with one layer of limestone 4 feet thick, and these 
again underlie Triassic sandstones. Both the Peel Sandstone and 
that of Penrith represent the Rothliegende, or Lower Permian of 
the Continent. The Stack Series may be referred either to the 
concluding phase of that subdivision, or to the beginning of the 
period of the Magnesian Limestone, so well developed on the 
eastern side of the Pennine Chain. 
LX, Tur SHEARING AND FAULTING. 
These Permian rocks are sheared and faulted to an extraordinary 
degree, and their presence on the coast-line of the Isle of Man is 
