caption: The image shows four different types of clams on a black background, with the text "Unio Bulbosus Lea, 1857, Holotype USNM 84715" at the top and bottom. The clams are arranged in a symmetrical pattern, with each one having a unique shell shape and texture. The shells are a light brown color with a glossy sheen, and the text is written in a bold white font.