Cassell's natural history, london, Cassell & Company, Limited, 1896, animals, otter, nomenclature, common otter, animal behavior European otter, Eurasian otter, old world otter, Lutra lutra, Two common otters are depicted in a serene natural setting, lounging on a rocky surface near the water's edge. One otter is lying comfortably with its back turned, while the other is seated, attentively looking towards the water. Surrounding them are lush foliage and textured tree branches, creating a peaceful habitat. The scene captures the playful and curious nature of these aquatic mammals, highlighting their sleek bodies and expressive features. The environment emphasizes the otters' connection to their habitat, showcasing a tranquil moment in the wild.