Most of the largest Cetacea belong to the group called “Whalebone Whales,” in which a series of horny plates termed “whalebone” grow from the palate in place of teeth, and serve to strain the water taken into the mouth from the small marine animals on which these Whales subsist. A representative of this group is the skeleton of the Common Rorqual or Fin-Whale (_Balænoptera musculus_) in the south-west portion of the room. This Whale, which is sixty-eight feet long, was captured in 1882 in the Moray Firth, Scotland. The flukes of the tail and the back-fin were preserved with the skeleton and are placed above the wall-case behind; the small pelvic bones, and a rudimentary nodule representing the femur or thigh-bone, the only trace of the hind leg of this gigantic animal, are also shown. The external form is modelled in plaster. In front is a skeleton and half-model of the Black or North Atlantic Right-Whale (_Balæna glacialis_ or _biscayensis_). Below this skeleton is placed a lower jaw of the Greenland Right-Whale (_Balæna mysticetus_), the species which formerly yielded most of the “whalebone” of commerce, and also a miniature wooden model of the entire animal, on the scale of one inch to the foot. Remains of extinct Cetaceans--notably the solid bony beaks of the skulls of Beaked Whales (_Ziphiidæ_) from the Red Crag of the east coast of England--are placed in this gallery. A special table-case, near the Sperm-Whale, shows the curious ear-bones of various Cetaceans, both recent and fossil. These bones are perfectly sufficient for the identification of the kind of Whale from which they were taken. In a case on the opposite side of the gallery is displayed the horny wart, termed by sailors the “bonnet,” found on the nose of the Black Right-Whale. FIRST FLOOR. The upper floors of the wings of the Museum consist merely of single galleries extending along the whole front of the building; for the galleries which run backwards on the ground floor form only a single storey. [Illustration: BRITISH MUSEUM (NATURAL HISTORY). First Floor. Second Floor.] [Sidenote: Lower Mammal Gallery.]