Inhab. Australia.
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.
Family 8. PLATANISTIDÆ.
Platanistidæ, Gray, l. c. pp. 62, 220; Synops. Whales & Dolph. p. 4.
Platanistinæ, Flower, Trans. Zool. Soc. vol. vi. p. 114.
Head long-beaked. Jaws slender, compressed. Skull—crown covered with the converging arch and reflexed edges of the maxillaries.
“Costal cartilages not ossified. The tubercular and capitular articulations of the ribs blending together posteriorly. Cervical vertebræ all free. Pterygoid bones thin, not conforming in their mode of arrangement with either of the other sections. Jaws very long and narrow; both with numerous teeth having compressed fangs. Symphysis of mandible very long, exceeding half the length of the entire ramus. Orbit very small. Lachrymal bones not distinct from the jugal. Pectoral limbs large. Dorsal fin rudimentary. Maxillary bones supporting large bony incurved crests. No cingulum or tubercle at the base of the crown of the teeth. Pectoral fins truncated. Visual organs rudimentary. External respiratory aperture longitudinal, linear.”—Flower.