French painting in the time of Jean de Berry : the Limbourgs and their contemporaries / by Millard Meiss, with the assistance of Sharon Off Dunlap Smith and Elizabeth Home Beatson
This is an imaginary story about a young turtle that goes to visit his friend the crab. The crab is looking for a bigger shell for himself because he has outgrown the shell that he has. Turtle decides that he also has to have a new shell. So the two friends move around the bottom of the sea trying on shells of various shapes and sizes until Turtle discovers that the best shell is the one he already has!