In 1793 John Stockton published his edition of John Gay’s “Fables” (a second edition, retaining the 1793 title-page, was produced c1811). The book was “embellished with Seventy Plates”. These were engraved by various artists after designs by William Kent and John Wootton from the first edition of Gay’s “Fables” from 1727, and after designs by Gravelot from a later edition with new fables (1738). Twelve of the plates in Stockton’s edition were engraved by Blake. Like the other engravers employed in the book, he used considerable artistic license in translating the earlier designs onto new copperplates. This impression is in the published volume of the “Fables”, the 1793 edition; the engraving is in the Prints & Drawings Department of the British Museum, and is an illustration to “Fable XXIV. The Butterfly and the Snail” in Gay’s “Fables”, Vol. 1 (London, 1793); a formal garden, with a gardener and a neo-classical building; in the right foreground a snail and a butterfly .
The full text of this fable is [2, p. 36]:
Butterfly and Snail.
The snail is a dextral specimen, with two larger tentacles and one of the smaller to be seen. The colour pattern does not match a well-known species, but this may be due to the “considerable artistic license” of the printmaker.
 BML, inv. PD 1856.0510.717. http://to.ly/FHrf.