"Carboniferous." . . . . . . . . . . "Memoirs of the Geological survey of Great Britain, &c. v. II. pt. II"@en . . . "On the vegetation of the carboniferous period, as compared with that of the present day"@en . . . "On the vegetation of the carboniferous period as compared with that of the present day"@en . . "VEGETATION MAPS AND SURVEYS." . . "From 280 to 345 million years ago" . .