a genus of animals of the Enterop-neusta class, Hemichorda subphylum. The body (up to 2.5 m long) is divided into the snout, the collar, and the body proper. In the USSR there is one species (up to 9 cm long), found in the Sea of Japan. It lives in the mud and sand of coastal sea waters. Representatives of other genera of the Enteropneusta class are also often called Balanoglossus, for example, the Saccoglossus mereschkowskii (up to 10 cm long), which lives in the White and Barents seas.