The Adélie Penguin, Pygoscelis adeliae, is a species of penguin common along the entire Antarctic coast. They are among the most southerly distributed of all seabirds, as are the Emperor Penguin. In 1840, French explorer Jules Dumont d'Urville named them for his wife, Adéle. These penguins are mid-sized, being 46 to 75 cm (18 to 30 in) in length and 3.6 to 6 kg (7.9 to 13 lb) in weight. Distinctive marks are the white ring surrounding the eye and the feathers at the base of the bill. These long feathers hide most of the red bill. The tail is a little longer than other penguins' tails. The appearance looks somewhat like a tuxedo. They are a little smaller than other penguin species. Their appearance is closest to the stereotypical image of penguins as mostly black with a white belly.