544 On the Fossil Fishes of the Carboniferous Limestone Series of Great Britain. 
named by Mr. G. Tate, the Tuedian, consists of red sandstone conglomerates, 
surmounted by red sandstones, and above them beds of limestone, shales, and 
clays, the uppermost bed being the Dun or Lamberton limestone, the whole are 
about 1,500 feet in thickness. The Upper group, several thousands of feet in 
thickness, for which the name Bernician beds has been suggested by Prof. Lebour, 
occupy a large area in the western part of the county, extending from the Cheviot 
hills and the sea coast at Berwick and Alnmouth, southwards to Hexham. The 
Bernician beds are the equivalents of the Yoredale rocks of North Yorkshire and 
the thick-bedded scar limestone of Settle and Derbyshire. ‘The Yoredale series 
in their progress northwards are largely developed. Thick massive grit rocks are 
intercalated with numerous beds of light bluish grey limestone, thick beds of shale 
and thin seams of coal. Fossils, principally mollusca of the ordinary Mountain 
Limestone species, are numerous throughout the limestones; crinoidsand foraminifera 
are not uncommonly met with. ‘The ‘‘four fathom limestone” and the “ great 
limestone” are extensively quarried at Lowick and along with a great number of 
species of invertebrates, several species of fish have been discovered. 
The Carboniferous Limestone series of the west of Scotland assume an entirely 
different arrangement to that of the beds in England or Ireland. The massive 
Scar Limestone is absent and a large portion of the beds are of fresh water or 
brackish origin. The following is the sequence of the beds beneath the Millstone 
grits — 
Upper Limestone Series. 
Lower Coals and Ironstones. 
Lower Limestone Series. 
Calciferous Sandstone Series. 
Old Red Sandstone. 
‘The Upper Limestone Series are between 506 and 600 feet in thickness and 
consist principally of thick sandstones, shales, clay ironstones and coals, with 
several beds of impure limestone; organic remains are abundant,consisting principally 
of mollusca, crinoids, foraminifera, corals, polyzoa and some fish remains. The 
Lower Coals and Ironstone are nearly related in lithological characters with the 
Upper Coal Measures. They are, with slight exceptions, of freshwater or terrestrial 
origin, consisting of sandstones, numerous bands of clay ironstone, shales and 
coals. The Lower Limestone Series most nearly approaches the Mountain Lime- 
stone in palzontological characters. It ranges from 600 to more than 1,000 feet 
in thickness and its lithological character is somewhat similar to that of the Upper 
Limestone Series at Beith in Ayrshire, some of the beds of limestone attain a 
thickness of more than 40 feet, but generally they are much thinner. One or two 
workable beds of coal, and numerous bands of clay ironstone, occur in several 
horizons of the strata. In some districts, as at Campsie, thin beds of estuarine, or 
