Bulletin of the United States National Museum. Ex-library book. Grubby paperback with creased rear cover. Foot of page block is grubby. Leading edges of pages are unevenly cut. Library plate and stickers on inside front cover. Library stamps on title page and BEP. Two light creases through upper edges of second half of pages. Minor creasing to lower leading corners of final pages. Binding is tight, and text remains clear throughout. T