This is so much more than a simple white and yellow shell drawing but to be honest with you, it seemed better to call it that than to call it cassis decussate – the name which was on the book plate. All I can find based on that name are other book plates and that cassis would seem to indicate the creature that called such an interesting shell its home was a mollusk and not some sort of snail.
The outside of the shell has a fairly uniform grid-like pattern. I would guess in real life that it might not be black lines as shown but ridges and valleys. Here and there across the grid are yellow squares that cover several cells of the grid. The mouth of the shell has fairly large lips and the inside of the shell appears to be striped in lovely shades of peach and red colors.
This vintage white shell drawing is one of a number of colored sea-life drawings from an 1822 natural history dictionary written by Jean Baptiste Geneviève Marcellin (1778-1846). The artist does not appear to have been identified.
This image is copyright free and in the public domain anywhere that extends copyrights 70 years after death or at least 120 years after publication when the original illustrator is unknown.