Paperback in very good condition in original grey wrappers. Reprinted from 'The American Midland Naturalist' Vol. 35, No. 3, pp. 545-727, May, 1946. A report on the structural differences in the bones and muscles of the locomotor apparatus of the genera of New World vultures (family Cathartidae) and to interpret these in relation to differences in habitat. Black and white illustrations and photographs.