Letters from Duncan, Peter Martin to Charles Lyell, 3 February 1866-19 January 1870

Letters are summarised by Lyell as:
1) Dr Duncan on Bolderberg Flabellum [relating to Bolderberg formation in Northern Belgium]
2) Tropical corals, how far corals can indicate climate
3) Corals in Norway sea
4) 60 new Liassic [Early Jurassic] corals, showing imperfection of record
5) Lonsdale notes and Keeling island [Cocos, Australia] specimens
6) Scleractinia of antigua corals and explanation of Duncan's theory
7) reference to his paper on corals
8) Corals dredged up by the 'Porcupine' [referring to HMS Porcupine expedition of Porcupine Bank, West Ireland] and Faroe Islands.