Diatomea–Schachtellinge from Kunstformen der Natur (1904) by Ernst Haeckel. Original from Library of Congress.… https://www.rawpixel.com/image/2272220/free-illustration-image-ernst-haeckel-sea-vintageFree Image from public domain licenseGroup of Tubularis Indivisa (1884) by Eduard Oscar Schmidt, an unusual aquatic life form. Digitally enhanced from our own… https://www.rawpixel.com/image/428217/free-illustration-image-sea-ocean-queerFree Image from public domain license