The specimens described in this paper were collected by Dr J. H. Harvey Pirie, B.Sc, M.B., geologist to the Scottish National Antarctic Expedition, during a short visit paid to Gough Island on the homeward voyage of the Scotia from the Antarctic seas in 1904. The island is not often visited, and the only previous account of the rocks is by Professor L. V. Pirsson, who described a series of beach pebbles collected by the captain of a whaling vessel. Among those Professor Pirsson noted two varieties of basalt, trachytic tuffs, and a trachytic obsidian carrying olivine, and shown by chemical analysis to be of phonolitoid type.

With the exception of a small fragment of limestone, the rocks in the Scotia collection are all igneous. They were obtained in the neighbourhood of the usual landing-place, the mouth of a small glen on the eastward side of the island. They include soda trachytes, trachydolerites, basalts, an essexite, and tuffs.