Note 154 — Chapter XII · CHARACTERS OF THE SILURIAN SYSTEM IN BRITAIN. THE ARENIG VOLCANOES
Reading edition
Mem. Geol. Surv. vol. iii. 2nd edit. p. 98; see also pp. 44, 54, 58, 71.
Reading edition
Mem. Geol. Surv. vol. iii. 2nd edit. p. 98; see also pp. 44, 54, 58, 71.