nearly the whole length of the jaws. Back rounded, 

 with a falcate dorsal fin, rarely absent. Skull with 

 the maxilla expanded over the orbit, and more or less 

 turned up on the edges. 



1. Pectoral fin elongate, falcate {except in Sotalia), acute 

 at the end ; hand as long as the arm-bones ; forearm- 

 bones close together, only separated by a straight line. 

 Carpal bones moderate, 5 or 7. 



Tribe I. STENONINA. 



Head beaked. Beak of the skull elongate, slender, com- 

 pressed. Nasal triangle short. Symphysis of the lower 

 jaw elongate. Gray, P. Z. S. 1866, p. 212. 



I. Pontoporia, Gray, I. c. 230, 231, 393, 1846. 



(Stenodelphis, Gervais, 1847.) 



Beak of the skull high, compressed. Symphysis of the 

 lower jaw very long. Dorsal fin ? Blowhole ? 



1. Pontoporia Blainvillii (T. 29, skull), Gray, I. c. 

 231 ; Flower, Trans. Zool. Soc. vi. 106, 1. 18 (skull) . Hab. 

 South Atlantic, Monte Video. 



II. Steno, Gray, I. c. 230, 232, 393, 394. 



Beak of the skull compressed, higher than broad. Sym- 

 physis of the lower jaw long. Marine and fluviatde. 



a. Skull large, solid, the beak compressed, high. Teeth 



large, conical, about two in an inch- of the length of the 

 margin of the jaw. 



1. Steno frontatus, Gray, I. c. 233. n. 3. Beak of the 



skull short ; the front part thick, high, and blunt. Teeth 

 24 . 24, large, two in an inch. Hab. Indian Ocean. 



2. Steno compressus (T. 27), Gray, I. c. 233. n. 4. 

 Beak of the skull elongate, compressed, attenuated in front. 

 Teeth 26 . 26, large, two in an inch (Zool. E. $ T. t. 27) . 

 Hab. South Sea. 



Steno rostratus appears to belong to this section. 



b. Skull small, rather spongy. Teeth small, slender, at- 



tenuated, about four or five in an inch of the length of 

 the margin of the jaw. 



* Beak of the skull elongate, compressed, much attenuated 

 and acute in front. Teeth four in an inch. Sousa 



3. Steno capensis, Gray, I. c. 394. n. 4*. Hab. Cape 

 of Good Hope. 



4. Steno lentiginosns, Gray, I. c. 394. n. 4**; Owen, 

 Trans. Zool. Soc. vi. t. 5. f. 2, 3. Hab. India ( IV. Elliot) . 

 Skull, B. M. 



The skull of Steno roseiventris, according to the figure, 

 appears to belong to this section of the genus. 



** Beak of the skull short, compressed, much attenuated 

 and acute in front. Teeth five in an inch. Tucuxa. 



5. Steno tucuxi, Gray, I. c. 237, 394. Hab. Brazil, 

 River Amazons, 1500 miles from the sea (Bates). 



See also S.? fiuviatilis and S.? pallidus, Gray, /. c. 237 ; 

 same locality, if distinct. 



*** Beak of the skull elongate, rather depressed, broad, 

 slightly compressed on the sides. Teeth small, five in 

 an inch. Stenella. 



6. Steno attenuates (T. 28), Gray, I. c. 235, 394. The 

 beak of the skull flattened (Zool. E. <S> T. t. 28) . Hab. 

 India. 



This last section is nearly intermediate between Steno 

 and Clymenia. 



Steno fuscus (T. 26. f. 1), only known from a foetus 

 in spirits. 



Tribe II. DELPHININA. 



Head beaked. Beak of the skull elongate, depressed, broad, 

 shelving on the sides. Nasal triangle short. Symphysis 

 of the lower jaw short, sloping. 



a Palate with a deep groove on each side behind. 

 I. Delphinus, Gray, I. c. 230, 393. 



Beak elongate. Dorsal fin distinct. Teeth small, 

 slender, five or six in an inch. (Foetus and tongue figured, 

 T. 26. f. 2) 



* Beak of skull twice as long as the brain-case. Teeth 



55 58 



55 0r 56- 



1. Delphinus longirostris, Gray, I. c. 241. n. 2. Hab. 

 Southern Ocean, Cape of Good Hope, Japan, Malabar. 



** Beak of skull once and a half the length of the brain- 

 case. Teeth % to f°. 



2. Delphinus delphis, Gray, I. c. 242. n. 3, 395. 

 Black, sides grey, beneath white. Hab. North Sea, North 

 Atlantic, Mediterranean. 



3. Delphinus Moorei, Gray, I. c. 396, fig. 99. Hab. 

 South Atlantic. 



4. Delphinus major, Gray, I. c. 396. Hab. ? 



5. Delphinus Walkeri, Gray, I. c. 397, fig. 100. Hab. 

 South Atlantic. 



6. Delphinus Janira (T. 23), Gray, I. c. 245, 398; Zool. 

 E. $ T. t. 23. Hab. Newfoundland. 



7. Delphinus pomeegra, Owen, Trans. Zool. Soc. vi. 

 t. 6. f. 3, t. 8. Hab. India (W. Elliot). Skull, B. M. 



