Dorsal fin low, broad; pectoral fin very long, with four very long fingers of many phalanges. Vertebræ 50 or 60; cervical vertebræ often anchylosed. Lateral process of the axis tardily ossified. Neural canal large, high, triangular. Ribs 14 or 15. 1. MEGAPTERA. Megaptera, _Gray_, _l. c._ pp. 113, 117; _Synops. Whales & Dolph._ p. 2; _Lilljeborg_, _N. Acta Upsal._ 1867, vi. Bladebone without acromion or coracoid process. Body of cervical vertebræ subcircular. 1. Megaptera longimana. B.M. Megaptera longimana, _Gray_, _l. c._ pp. 119 (fig.), 373; _Synops. Whales & Dolph._ p. 2. Megaptera boops, _Gray_, _Synops. Whales & Dolph._ tab. 30 (baleen and jaws with rudimentary teeth), t. 33. f. 12 (vertebra). Inhab. North Sea. 2. Megaptera Novæ-Zelandiæ. B.M. Megaptera Novæ-Zelandiæ, _Gray_, _l. c._ p. 128, fig. 20; _Synops. Whales & Dolph._ p. 2. Inhab. New Zealand. Ear-bones in Brit. Mus. 3. Megaptera? Burmeisteri. Megaptera? Burmeisteri, _Gray_, _Cat. Seals & Whales_, p. 129. Megaptera Lalandii (part.), _Van Beneden_, _Ostéogr. Cét._ Inhab. Buenos Ayres. Skeleton, Mus. Buenos Ayres. 4. Megaptera americana. Megaptera americana, _Gray_, _Cat. Seals & Whales_, p. 129. Inhab. Bermuda. “The _norwega_ is a Humpback which has the belly white and smooth (?), back very dark bluish, length 50 to 55 feet. This whale gives more oil than the mystica.”—_Hartt_, _Geology & Physical Geography of Brazil_, p. 182. “The whalebone is short, and sells well. The beach on which the whales are cut up is strewed during the season with bones. There must be the bones of 500 whales on the spot. The fishery is carried on at Bahia on a much larger scale than at Caravellas.”—_L. c._ p. 185. 5. Megaptera kuzira. Megaptera kuzira, _Gray_, _Cat. Seals & Whales_, p. 130. Inhab. Japan. Skull, Mus. Leyden. 6. Megaptera osphyia. Megaptera osphyia, _Cope_, _Proc. Acad. Nat. Sci. Philad._ 1865, p. 4. Inhab. Atlantic. Skeleton. Mus. Niagara. “A second and more full examination of the _Megaptera osphyia_, Cope, furnishes the following additional points and characters. The specimen is young, and measures in its present condition 34 feet. It has, however, lost a considerable number of caudal vertebræ, and, from the posterior part of the column, of intervertebral cartilages also; add to this the shrinking of the cartilages preserved, and the increase of length would perhaps amount to 8 feet, giving 42 in all. The asserted length of 50 feet, line measurement, which I quoted in my original description, is no doubt an exaggeration.