Manuel d'actinologie ou de zoophytologie, Paris, F.G. Levrault, 1834-1836, corals, sea anemones, cnidaria, ctenophora, This illustration depicts a holothurian, commonly known as a sea cucumber, showcasing its elongated, tubular body adorned with fine, hair-like structures. Key features include the external texture and the distinct ending, which resembles a mouth surrounded by circular formations. Various numbered sections indicate specific anatomical details, such as the arrangement of the tentacles and cross-sectional views that highlight the organism's complex structure. The intricate design emphasizes the sea cucumber's unique adaptations to its marine environment.