Cetacea and two (external) limbs that are modified into flippers. Though not as flexible or agile as seals, cetaceans can swim very quickly, with the killer whale able to travel at in short bursts and the fin whale able to cruise at . Dolphins are able to make very tight turns while swimming at high speeds. The hindlimbs of cetaceans are internal, and are thought to be vestigial. Baleen whales have short hairs on their mouth, unlike the toothed whales. Cetaceans have well-developed senses—their eyesight and hearing are adapted for both air and water, and baleen whales have a tactile system
Two Forms (Divided Circle) Two Forms (Divided Circle) Two Forms (Divided Circle) (BH 477) is a bronze sculpture by Barbara Hepworth, designed in 1969. Six numbered copies were cast, plus one (0/6) retained by the sculptor. The sculpture's dimensions are by by . The front of the base has "Barbara Hepworth 1969" inscribed on it followed by the number of the sculpture, as well as "Morris | Singer | FOUNDERS | LONDON", both inscribed by casting. The sculpture is considered to be one of Britain's most recognisable works. The sculpture is late work by Hepworth, created only 6 years before her death in a