Note 271 — Chapter XIV · THE SILURIAN VOLCANOES OF IRELAND
Reading edition
See Sheet 49 Geol. Survey, Ireland, and Explanation thereto (1871), pp. 16, 37, 39. The so-called "ashes" of the Explanation are probably parts of dykes which have been more or less crushed.
[272] Guide to the Collection of Rocks and Fossils belonging to the Geological Survey of Ireland, by Messrs. M'Henry and Watts, Dublin, 1895, p. 74.