During the flight down from the window his form recomposed itself for an instant, in the air one could have seen dancing a quadruped with long whiskers, and its right foreleg seemed to be raised in imprecation. Then all found peace in a heap of livid dust. (8.56)
In the final moments of this book, Concetta—one of the last surviving members of the Salina family—glances outside and thinks she sees a leopard running in the air. She realizes her mistake when she sees that the figure is just her old stuffed dog Bendicò getting thrown into the trash.
This awesome ending basically sums up the entire book. The Leopard has shown us a glimpse of the gracefulness and pride (i.e. leopard-like qualities) that used to belong to the Salina family. Now like Bendicò, the Salina family has been thrown into the garbage can of history. That's just the way history works, folks: it's brutal.