"From 405 to 425 million years ago" . . "From 405 to 500 million years ago" . . . "Siluria : the history of the oldest fossiliferous rocks and their foundations : with a brief sketch of the distribution of gold over the earth" . . "Siluria : the history of the oldest fossiliferous rocks and their foundations; with a brief sketch of the distribution of gold over the earth" . . . . . "Siluria : The History of the oldest Fossiliferous Rocks and their Foundations ; with a brief sketch ... ; including \"The Silurian System\", with maps, and many additional illustrations" . "Siluria the history of the oldest fossiliferous rocks and their foundations with a brief sketch of the distribution of gold over the earth" . "Siluria. The history of the oldest fossiliferous rocks and their foundations" . "Siluria : the history of the oldest fossiliferous rocks and their foundations, with a brief sketch of the distribution of gold over the earth"@en . . . "Siluria : the history of the oldest fossiliferous rocks and their foundations"@en . . . . . . . . . . "Murchison's Siluria"@en . . . . "Siluria : the history of the oldest fossiliferous rocks and their foundations with a brief sketch of the distribution of gold over the earth" . . . "Silurian system" . "Siluria, the history of the oldest fossiliferous rocks and their foundations, with a brief sketch of the distribution of gold over the earth"@en . . . . . "Silurien." . .