Note 453 — Chapter XIII
Reading edition
See Salter on Pterygotus, Quart. Journ. Geol. Soc. vol viii p. 387.
[454] Dr. Harlan, in Trans. Geol. Soc. Pennsylvania, vol. i. p. 96.
[455] See the elegant Memoir on the Fresh-water Limestone of Burdie-house, near Edinburgh, by Samuel Hibbert, M.D. F.E.S.E.