Data di pubblicazione: 1945
Da: Willis Monie-Books, ABAA, Cooperstown, NY, U.S.A.
Softcover. Condizione: Very Good-. Off Print. Ex-library copy with ink stamp on the front cover. Also a private owner's name ink stamp on the front cover. Bending to the lower outer corners. ; Original paper covers. Signed by Stewart on the front cover. Off print, two titles issued together. Reprinted from the Journal of Paleontology, Vol. 19, No. 2, March, 1945.