Editore: USGS Professional Paper 220, 1950, vi + 200 pp. + folded plate., 1950
Da: Eryops Books, Stephenville, TX, U.S.A.
Soft Cover. Condizione: Fair. ORIGINAL 1950 PUBLICATION; Softcovers; ex-library; missing plates 1 thru 4 from rear pocket; bound in light cardboard; cardboard cover and front wrap w/ large tear along lower corner; large portion of rear cardboard missing (but original rear wrap present); light dampstains on lower corners; corners lightly creased w/ several dogears; edges of rear pocket split.