60 CETACEANS. 
small species, not exceeding 4 feet in length, with forty-eight teeth on each side of 
the jaws, which has a skull intermediate between that of the common dolphin 
and the next species. The slender dolphin (D. attenwatus) may be taken as an 

RED-BELLIED DOLPHIN. 
(From True, Bulletin of the U.S. National Museum, 1889.) 
example of a group of several species, distinguished from the common dolphin 
and its allies by the palate being nearly flat, instead of deeply hollowed on each 
side in its posterior portion. Most of them are further distinguished by the skin 



























THE SLENDER DOLPHIN. 
(From True, Bulletin of the U.S. National Museum, 1889.) 
being either spotted, or marked with longitudinal bands. The slender dolphin is: 
a spotted species from the Atlantic and the Cape of Good Hope; while the Malayan 
dolphin (D. malayanus), from the Indian Ocean, which attains a length of 6} feet, 
is uniform ashy grey. 
THE BotTTrLE-NOSED DOLPHINS. 
Genus Tursiops. 
The bottie-nosed dolphin, or, as it is often incorrectly called, porpoise (7ursiops 
twrsio), is the best known of three or four species constituting a genus distinct from 
Delphinus. The general form of these dolphins is stout, with the beak shorter and 
more tapering than in the true dolphins, and the number of teeth considerably less 
—not exceeding from twenty-two to twenty-six on each side of the jaws. 
The bottle-nosed dolphin attains a length of from 9} feet to 12 feet. In colour 
it is usually purplish grey above, passing gradually into pure white on the under- 
parts; but some specimens are black above and pale grey below, while others are 
grey all over. 
