[ Archibald Geikie, Scottish geologist. ] Autograph Letter Signed ('Arch Geikie') to a female student of geology, correcting the misidentification of two specimens.

2pp., 12mo. Bifolium. In good condition. The recipient is not identified. The letter begins: 'Dear Madam | It always gives me pleasure when I can in any way assist a student of Geology, and the pleasure is not lessened when the student is a young lady.' He proceeds to explain how the two specimens about which she has written to him ('Frigonia incurva' and 'Pleuromya Voltzi') have been wrongly identified, concluding: 'Your specimens appear from your drawings to be only casts and may therefore be difficult to determine satisfactorily.'