Suborder IV. SUSUOIDEA.

Susuoidea, Gray, Synops. Whales & Dolph. p. 4.

Head beaked. Nostrils longitudinal, each covered with a valve (the right often obliterated). Teeth in upper and lower jaws, compressed. Crown of skull covered with a bony arch. Pectoral fin broad, truncate. Fingers 4, nearly equal, the outer the shortest.