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Keywords from Image Description:
The Quarterly journal of the Geological Society of London . Tigs Sketches from the SMddaw Slates Natural size Phyttograptus Hall Teiragropsus gen nov is the typical form may possibly be form of Dichograpsus Vichograpims arauea Salter Dwhograpsus Salter with its corneous cup froui Lopan Dichograpsu Sedgtrickii Salter Branchlet