This is a slightly different W. W. Denslow cover, created for a Rand McNally printing of The Merchant Prince of Cornville. This is stated to be a fourth edition of the book, and has an introduction dated 1899 - so it's a little past the general time frame of 1896 to 1898 when Denslow was regularly producing covers for the company. I find this cover interesting, because it isn't what I generally think of for a Denslow piece. It has a paper label, rather than a stamped image, and in fact, I suspect it may be something the publishers put together without Denslow's input.
The first Rand McNally printing of this book from 1896 was very plain, with only the title on the front cover. This is a play, rather than a novel, and is said to have been plagiarized by Edmond Rostand in 1897 for his well-known drama Cyrano de Bergerac. At any rate, Samuel Gross sued Rostand over his play, and won the case.
I know this is a Denslow piece because the artist created a color poster for this book, featuring the same lettering and image seen on the paper label - the photo on the right is from the New York Public Library digital gallery. The poster is clearly signed with the Denslow seahorse, something which is lacking from the book cover. My thought is that the publishers simply pulled elements from this poster for the cover seen on the edition of the book shown above, which would explain the difference from so many of Denslow's other covers.