Dorsal fin high, erect, compressed, about two-thirds of the entire length from the nose. Pectoral fin moderate, with four short fingers. Vertebræ 50; cervical vertebræ sometimes anchylosed. Neural canal broad, trigonal. Ribs 11·11. The second cervical vertebra with a broad lateral expansion, perforated at the base. First rib single-headed. Lower jaw with a conical coronoid process. 1. BALÆNOPTERA. Balænoptera, _Gray_, _l. c._ pp. 114, 186; _Synops. Whales & Dolph._ p. 3. Fabricia, _Gray_, _l. c._ p. 382. The lower lateral processes of the third to the seventh cervical vertebræ with an angular projection on the lower edges. Fingers short, the length of the forearm-bone. Scapula broad; acromion and coracoid elongate, slender. 1. Balænoptera rostrata. B.M. Balænoptera rostrata, _Gray_, _l. c._ p. 188, figs. 49-53; _Synops. Whales & Dolph._ p. 3, t. 1. f. 5 (baleen), t. 2 (skull), t. 32. f. 3, 4 (cervical vertebræ); _Van Beneden_, _Ostéogr. Cét._ t. 12 & t. 13. figs. 1-10. Inhab. North Sea. 2. Balænoptera velifera. Balænoptera velifera, _Cope_, _Proc. Acad. Nat. Sci. Philad._ 1869, p. 18, f. 9, 10. Dorsal fin large. Inhab. Oregon (Finner Whale); California, Queen Charlotte’s Sound. 2. SWINHOIA. Swinhoia, _Gray_, _l. c._ p. 382; _Synops. Whales & Dolph._ p. 3. The lower lateral processes of the third to the sixth cervical vertebræ slender, regularly curved, without any prominent angle on the lower edge. 1. Swinhoia chinensis. B.M. Balænoptera Swinhoei, _Gray_, _l. c._ p. 382, figs. 88-93. Swinhoia chinensis, _Gray_, _Synops. Whales & Dolph._ p. 3. Inhab. Formosa. Section II. DENTICETE (_cf._ p. 35). Denticete, _Gray_, _l. c._ pp. 62, 194; _Synops. Whales & Dolph._ p. 3. Odontoceti _or_ Delphinoidea, _Flower_, _l. c._ p. 111. Teeth well developed in one or both jaws, sometimes deciduous. Palate without baleen. Head large or moderate, compressed. Tympanic bones two, dissimilar, separate, becoming united, sunk in a cavity in the base of the skull. Gullet large. The suborders in this section have certain relations to each other by which they may be arranged in two parallel series:— | A. Nostrils | B. Nostrils | separate, | united, | elongated. | transverse. | | Teeth only in the lower jaw. Cervical | | vertebræ often united | Physeteroidea. | Ziphioidea. Teeth well developed in both jaws. | | Jaws beaked | Susuoidea. | Delphinoidea. Division I. _Nostrils longitudinal, parallel or diverging; each covered with a valve_ (cf. p. 62).