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APPENDIX. 
A. — Table showing the Vertical range of the Silurian Fossils of Britain. 
In the Appendix to the First Edition of this work, the range of those species 
only which are common to the great divisions Upper and Lower Silurian was 
exhibited in a tabular form. I am now enabled to give a complete list, so far 
as our present knowledge extends, of all the species, and to particularize their 
occurrence in the Subdivisions of the System — thus following the plan adopted 
in the original ' Silurian System.' 
Mr. J. W. Salter, aided by Prof. Morris, in the year 1859 compiled the Table 
published in the last edition. In the reconstruction of the Table for the present 
volume nearly 300 new forms have been incorporated with the previously known 
Silurian Fauna. Several published species are omitted, because a careful ex- 
amination has shown their identity with others previously described. The list 
now comprises all the hitherto well known British Silurian fossils, and shows 
their range throughout the different subdivisions. 
It is to be understood that Mr. Salter, who prepared the last edition of this 
Table, is not responsible for any inaccuracies it may contain in its present form. 
The additions and emendations have been chiefly made by Mr. Etheridge, assisted 
by Prof. Morris and Prof. Jones. The student will observe that many of the long- 
known names of Silurian fossils have been exchanged for more correct names 
according to the recent determinations of their real alliances, often obscure before, 
and only established on the discovery of more perfect specimens, and by an extended 
knowledge of extinct forms of life. To the paleeontological labours of Mr. Salter 
and Mr. Davidson we owe many of the more exact recognitions that have lately 
been made of the relationships of various Trilobites, Mollusks, and other fossils, 
as well as many descriptions of newly discovered forms. See especially David- 
son's ' Monograph on the Silurian Brachiopods,' and Mr. Salter's ' Monograph of 
the British Trilobites,' ' Appendix to Ramsay's Geology of North Wales,' &c. Mr. 
Davidson has examined the list of published Brachiopods, and Dr. Duncan that 
of the Corals ; Mr. Carruthers has revised the Graptolites, and Mr. Henry Wood- 
ward the Eurypteridae ; and the improved nomenclature advanced by these and 
other palaeontologists has been adopted in the body of the work. In the Expla- 
nations of the Plates, also, many of the old names will be found to have been 
exchanged for others more correct as to generic and specific affinities, or entitled 
to use by priority. 
The Lingula-flags (M. Barrande's 1 Zone Primordiale ' of the Silurian rocks, 
* Primordial Silurian ' of the Table) have, as explained in the body of this work, 
their fullest development near Tremadoc, Barmouth, and Dolgelly, in North 
Wales, and in St. Bride's Bay, south of St. David's, on the west coast of Pem- 
broke in South Wales. In the Silurian tract of Shropshire they are, in my 
opinion, represented by the dark schists which underlie the Stiper Stones, and 
are superposed to the greatest mass of the Cambrian strata known in England 
and Wales, namely, the Longmynd. 
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