caption: The image shows four different types of mussels, with the text "myctopus iridineus heude, 1874 USNM 472445" at the top. The mussels are arranged in a symmetrical pattern, with each one having a unique shape and texture. The colors range from light to dark, with some having a glossy sheen and others having a matte finish. The text is written in a bold, black font, making it stand out against the light background.