Note 116 — Chapter XI · THE CAMBRIAN VOLCANOES OF NORTH WALES, THE MALVERN HILLS AND WARWICKSHIRE
Reading edition
Quart. Journ. Geol. Soc. vol. xxxiv. (1878), p. 137.
[117] Prof. Bonney, op. cit. vol. xxxv. (1879), p. 316; Dr. Hicks, ibid. p. 296.
[118] Op. cit. vol. xliv. (1888), p. 278.