The Ancient Volcanoes of Great Britain, Volume 1 (of 2)Note 170 — Chapter XII · CHARACTERS OF THE SILURIAN SYSTEM IN BRITAIN. THE ARENIG VOLCANOESReading editionTrans. Roy. Soc. Edin. xxii. (1860), p. 636.◇Copy noteReturn to CHAPTER XII CHARACTERS OF THE SILURIAN SYSTEM IN BRITAIN. THE ARENIG VOLCANOES