YOU ARE BUYING A HB BOOK - SMITHSONIAN INSTITUTION (UNITED STATES NATIONAL MUSEUM) BULLETIN OF THE UNITED STATES NATIONAL MUSEUM NO 50 PART IV: THE BIRDS OF NORTH AND MIDDLE AMERICA, A DEXCRIPTIVE CATALOGUE, BY ROBERT RIDGWAY (1907). PLEASE SEE MY OTHER ITEMS FOR SALE, WHICH I AM UPDATING ALL THE TIME AND ADD ME TO YOUR LIST OF FAVOURITE SELLERS.