1965. Revised Editon. 240 pages. Beige and green dust jacket over green cloth. Royal Society of Canada Special Publications No. 3. Contains black and white in-text illustrations. Pages are lightly tanned and foxed throughout. Previous owner's inscription to front free endpaper. Binding remains firm. Boards have mild edge wear with slight rubbing to surfaces. Soft crushing to spine ends. Light tanning to spine and edges. Unclipped jacket has moderate edge wear with chips, tears and creasing. Rubbed marking to surfaces. Mild tanning to spine and edges.