1968. Fourth Edition. 64 pages. Illustrated dust jacket over blue cloth boards. Gilt lettering. Contains black and white plates. Clean pages and plates with light tanning and mild foxing throughout. Minor tanning to free endpapers due to dust jacket flaps. Binding remains firm. Boards have mild edge-wear with slight rubbing to surfaces and bumping to corners. Gilt lettering is darkened. Minor sunning to spine and edges with crushing to spine ends. Visible wear marks to boards. Unclipped jacket. Panels and spine have light edgewear with tears and creases. Minor loss to spine and edges. Visible wear marks to spine and panels.