BRITISH 
SILURIAN BRACHIOPODA. 
PRELIMINARY OBSERVATIONS. 
We now conclude our series of Monographs by treating of the Brachiopoda of 
the Upper and Lower Silurian strata; including therein all that vast series of deposits 
which, commencing at the base of the “ Lingula-flags,” extend to the uppermost 
bed of the “ Ludlow Series.” This important subject has attracted the serious atten- 
tion of many distinguished geologists as well as paleontologists; and at my request 
Sir Roderick Murchison has kindly written, as an Introduction to the present Mono- 
graph (p. 19), a concise account of his classification of the Silurian rocks, which will 
enable the reader better to understand the distribution in time and space of the many 
species we shall have to describe. 
It is well known to every geologist and paleontologist both at home and abroad, 
that prior to the publication of that truly classical and splendid work, ‘The Silurian 
System, in 1839, but little attention had been given in Great Britain to the fossils of 
the Lower Paleozoic period, and but few of the species had been correctly described and 
illustrated. Not so, however, upon the Continent, where a certain number of the 
beautifully preserved Swedish, Russian, and other Silurian forms, had for many years 
previous to the appearance of Sir R. Murchison’s celebrated work attracted the keen 
attention of Linnzeus, and- afterwards of others, who, in several works to be named in the 
sequel, had both figured and described a considerable number of Brachiopoda, of which 
a certain proportion were subsequently found to be identical with those so abundantly 
spread in the Silurian deposits of this country, as well as in those of many other regions. 
But in no instance had any foreign naturalist indicated the exact place in the geological 
series occupied by these ancient remains. In England prior to the publication of ‘The 
Silurian System’ very few of the Brachiopoda of that extended period had been 
I! 
