As all three commenters worked out, this month’s crocodile image is of printer’s waste used as endleaves. You can see the end of the book on the left side of the opening below (note the “finis” marking the end of the text) and the quarto imposition of the scrap paper used as part of the binding on the right side (note the brown-stained holes near the right edge, left by the clasps that were once there): Printer’s waste is not an unusual thing to see in bindings from this period. Paper was needed to create the binding structure, leftover paper from printing books is available, and voilà! Waste not, want not. Why was there so often scrap paper from the printing process? One reason has to do with the practice of printing by sheets, which are then assembled into gatherings and into the final book: if you want 500 copies…