PORPOISES AND DOLPHINS 321 



the flipper to the side of the throat. Flippers, back fin and tail 

 flukes are dark. A grey area covers the side from the eye to 

 behind the back fin. It is widest at the middle, tapering at 

 each end and is defined from the belly whiteness by a darker 

 streak. There is a smaller elongated light or white area on the 

 sides between the back fin and tail. Its forward end is above the 

 hinder end of the anterior patch, its hinder is near the origin 

 of the flukes, and it is separated from the white of the belly by 

 a broad, dark band. 



This species is found in the neighbourhood of Cape Horn, 

 Chile, Patagonia and the Falkland Islands. 



THE WHITE-BEAKED DOLPHIN (Lagenorhynchus 

 albirostris). PI. VIII c. 



The White-beaked Dolphin may be recognized by the 

 description expressed in its common name. The body form is 

 not unlike that of the White-sided Dolphin, but the ridges 

 behind back fin and vent are not so pronounced. The under 

 margin of the flippei is less curved and the back fin somewhat 

 higher and more reclined than in the White-sided Dolphin. 

 The beak, 2 inches in length, is made conspicuous by its 

 lightness of colour. The margin of the upper lip is dark grey 

 or black, and some pigment may be found on the lower lip as 

 well. The flippers are black on both surfaces, and are usually 

 inserted on the extension on to the sides of the pigmentation 

 of the back. Variation occurs, however, so that grey may be 

 found above the flippers, and a streak of dark pigment 

 connecting base of flipper and angle of mouth. 



Twenty-seven' teeth are present on each side of upper and 

 lower jaws — 22 to 25 of which are usually visible. They are 

 more massive than those of the WTiite-sided Dolphin, having 

 a diameter of about a quarter of an inch. 



The total length of the adult is 9 to 10 feet. 



The White beaked Dolphin is a northern species, its range 

 being very similar to that of the White-sided Dolphin, including 

 the North Atlantic Ocean, Baltic Sea, Faroe Islands, Green- 

 land, Davis Strait and the British coast. Nearly every British 

 stranded specimen has been recorded on the east coast, very 

 few indeed on the western, or Atlantic coast. 



