182 THE NATURAL HISTORY OF 



its age ; but when full grown, as the one exhibited in 

 the engraving, it is then above twenty feet long. The 

 great size of the dorsal fin, from which the animal de- 

 rives its name, distinguishes it among the dolphins as 

 much as a similar organ does the Physeter Tursio (or 

 finned Cachalot) among the Cachalots. 



These animals are found in Davis's Straits, on the 

 coasts of America and Spitzbergen, in troops from six 

 to eight. They generally live on fish, but the young 

 Balsena Mysticete is assailed on all sides by them. This 

 peaceable animal is tormented, harassed, and even 

 forced to succumb to the attacks of these audacious 

 adversaries j for, when he opens his mouth for the pur- 

 pose of respiration, in a moment these grampuses seize 

 upon his tongue with the greatest fury, and tear it to 

 atoms. 



The grampuses have frequently been captured in the 

 River Thames. — In 1759 and 1772, two common gram- 

 puses were taken 5 and in 1793 six of the sword species 

 were caught in the same river, one of which, after 

 making considerable resistance, was ultimately destroyed 

 near Greenwich : it measured thirty-one feet in length, 

 and twelve feet in circumference. 



SPECIES V. 



' DELPHINUS BIDENTATUS, 



OR 



THE TWO-TOOTHED DOLPHIN.* 



The body of this species is conical. The dorsal fin is 

 spear-shaped. There are two sharp teeth in the lower 



* Synonymus. — he Dauphin a Deux Denis, Bonnaterro. Delphimt* 

 Bidentatvs, La Cepede. 



