I Should not have presumed to publish an opinion as to the geological position of the roacks of Casterton Low Fell without having examined the typical region of Coniston and Windermere, had not Mr. Woodward thought it desirable to notice the occurrence there of a species of Ceratiocaris and asked me to furnish him with a note on the bed from which I obtained it. Having therefore collected all the evidence I could in that Limited and complicated area, I now, with the permission of the Director of the Survery, send him some extracts from my notes, which may be of interest, as showing the character and relations of the rocks there seen.