'Symmetrical as the fossilized imprint of a trilobite'

One day, Mother returned home from town with a preoccupied face.

'Look, Joseph,' she said, 'what a lucky coincidence. I caught him on the stairs, jumping from step to step --' and she lifted a handkerchief that covered something on a plate.  I recognized [Father] at once. The resemblance was striking, although now he was a crab or a large scorpion. Mother and I exchanged looks: in spite of the metamorphosis, the resemblance was incredible...

...She put the plate down, and leaning over him, we observed him closely. There was a hollow place between his numerous curved legs, which he was moving slightly. His uplifted pincers and feelers seemed to be listening. I tipped the place and Father moved cautiously and with a certain hesitation onto the floor. Upon touching the flat surface under him, he gave a sudden start with all of his legs, while his hard arthropod joints made a clacking sound...

-- from Father's Last Escape by Bruno Schulz. Nicole Kraus reads the story and discusses it with Deborah Treisman here.