This watercolor is by Christophe-Paulin de La Poix de Fréminville, likely painted between 1822 and 1839 based on animals from the Eastern Atlantic. It was probably meant for a naturalist study never completed. The lower crab is titled “l'Uca de Marcgrave” with the species name Ocypoda Uca.. Not a fiddler crab, this is clearly a painting of the mangrove crab Ucides cordatus whose name has so often been mixed up with the fiddler crab genus (as described elsewhere on the site).The upper crab is clearly a swimming crab from the family Portunidae; I don't know whether it is simply the Atlantic Blue Crab (Callinectes sapdius) or another species from that family. The given name, which is not a recognized name or synoynm, refers to the four spots on the carapace.
This image is taken from the website of the Amon Carter Museum of American Art, Fort Worth, Texas, where the original watercolor is currently held in storage.
