RT Journal Article SR Electronic T1 XXII. Memoranda relative to the Porphyritic Veins, &c. of St. Agnes in Cornwall. JF Transactions of the Geological Society of London JO Transactions of the Geological Society of London FD Geological Society of London SP 401 OP 403 DO 10.1144/transgsla.4.401 VO S1-4 IS 1 A1 CONYBEARE, J. J. YR 1817 UL http://trn.lyellcollection.org/content/S1-4/1/401.abstract AB