Family 15. PONTOPORIADÆ.
Head long-beaked. Beak slender, smooth. Nostrils on the nape, crescent-shaped. Teeth in both jaws permanent, conical, with a swollen ring round the base. Dorsal fin short, trigonal. Pectoral fin short, truncated. Fingers 5, nearly equal; the thumb very short, of one joint; the index finger the longest, the rest gradually shorter to the little finger. Bladebone broad, with two ridges. Skull long-beaked, the beak compressed. Lower jaws united together nearly to the base. Cartilages of ribs ossified.
Vertebræ 42:—C. 7. D. 10. L. 7. C. 18.
1. PONTOPORIA.
Pontoporia, Gray, Cat. S. & W. pp. 230, 231 & 393; Synops. Whales & Dolph. p. 5; Flower, Trans. Zool. Soc. vi. p. 87; Burmeister, An. Mus. P. Buenos Ayres, p. 389.
Stenodelphis, Gervais, 1847.
Beak of the skull high, compressed. Symphysis of the lower jaw very long.
1. Pontoporia Blainvillii.
B.M.
Pontoporia Blainvillii, Gray, l. c. p. 231; Synops. Whales & Dolph. p. 5, t. 29 (skull); Flower, Trans. Zool. Soc. vi. p. 106, t. 28 (skull); Burmeister, An. Mus. P. Buenos Ayres, i. p. 387, tab. 23 (animal), tab. 25 & 26 (skeleton).
Inhab. South Atlantic, Monte Video.
The animal figured by Gervais as Delphinus (Stenodelphis) Blainvillii (Voy. Amér. Mérid. t. 23) differs from Burmeister’s figure in having an elongated subfalcate pectoral fin, and a higher dorsal, and a broad white streak, commencing from the blower and extending down the back to near the tail. If this is not a figure of the animal seen at sea, which I suspect it must be, it must be a different species.