PORPOISES AXD DOLPHIXS. 57 



with distinct beaks, ani 1 remarkable for their stn rogly-contrasting coloration. They 

 are generally characterised by the head having a short and not very well-defined 

 ploughshare-like beak, although in one species the head is pointed and beakless. 

 The fin and flippers are of moderate size; and the tail has very prominent ridges. 

 The teeth are variable in size and number ; the beak of the skull is flat, and not 

 longer than the hinder part of the same ; and the onion between the two branches 

 of the lower jaw is short. The coloration takes the form of two light-coloured 

 areas of variable size on the sides, separated from one another by irregular, oblique 

 dark band-. Representath es of this genus are found in most of the temperate and 

 tropical seas, and two species have been taken oti'the British coasts. 

 white-Sided Of the two British species, the white-sided dolphin (Lageno- 



Doiphin. rhynchua acutus), is blackish grey above, and white beneath, with 

 a broad band of yellowish brown between the two, in the middle of which is a 

 large white patch: while a narrow black band extends from the flukes nearly 

 to the line of the back-fin. and another runs from the base of the flipper to a point 



THE PACIFIC SHORT-BEAKED DOLPHIN. 



(From True, Bulletin of the U.S. National Museum, 1889.) 



between the eye and the mouth ; the eye being surrounded by a black ring. The 

 length varies from G to 8 feet. This species inhabits the North Atlantic and the 

 North Sea. It is very rare on the British coasts, although said to be not unfre- 

 quently seen oft' the Orkneys. 



Pacific snort- The species figured to represent this genus (L. crucigeru) is one 



Beaked Dolphin. f nim the Pacific, which is selected on account of the marked contrasts 

 of black and white. It has a short beak, only slightly marked oft" from the skull. 

 In colour, the muzzle, the forehead, the back, and the fin, flippers, and flukes are 

 black ; while a broad black band runs from the eye and the base of the flipper 

 along each side to the flukes ; the other parts of the body being a more or less 

 pure white. 



White-Beaked The second species of this genus which has been met with on 



Dolphin. the British coasts is the white-beaked dolphin (L. albirostris) ; this 

 species resembling the white-sided dolphin in general form, but having a more 

 swollen head, a narrower and more sloping back-fin, and longer flippers. It takes 

 its distinctive name from the fact of the muzzle, including the extremities of both 

 jaws, being white, more or less tinged with grey. The upper-parts are black, the 

 sides greyish, and the under-parts white, frequently of a creamy hue ; while there 

 are three more or less distinctlv defined whitish areas on the flanks, placed one 



