$8 THE BRITISH MAMMALS : THEIR GENERA AND SPECIES, 



markings taking the form of whitish oval rings on the back and 

 flanks. The head is rather narrow. The teeth have intervals 

 between them, and are not obliquely set in the jaw; the branches of 

 the lower jaw, as in the Harp Seal, are parallel to begin with ; the 

 premaxillaries are laterally contiguous with the nasals ; and the 

 hinder edge of the palate is deeply notched, as in the Common Seal. 

 The thumb is noticeably longer than the other digits. This species 

 is a summer visitor from the far north, where it frequents the coast 

 and breeds on the ice, the young never more than one a year being 

 born in the early spring. It is found in the North Pacific as well as 

 in the North Atlantic. 



The Harp Seal is from five to six feet long. In colour it is a pale 

 tawny or yellowish grey with a dark half-moon on the shoulder and 

 flank, the two curves forming the so-called "harp" or "saddle." 

 In the females the mark is generally present but much less distinct ; 

 the males being otherwise distinguishable by their black faces. The 

 head is rather dog-like. The teeth are not set obliquely, and are 

 well spaced ; the branches of the lower jaw, owing to the long 

 symphysis, nearly meet for a third of the length ; the premaxillaries 

 are not laterally contiguous with the nasals ; and the hinder edge of 

 the palate is not notched or only faintly so. This is the Greenland 

 Seal, another summer visitor from high latitudes. Unlike the 

 Ringed Seal it does not frequent the ice-bound coasts of the north 

 and betake itself to the floes when the ice breaks up for its young to 

 be born on them, but chooses the fields and floes in the open sea as 

 if they were so many islands. It is, however, only certain regions of 

 the Arctic that it visits as its breeding grounds, and thither it 

 migrates in thousands every year. It differs from the Ringed Seal, 

 also, in never making a breathing-hole, for unlike that species it 

 does not get under the ice, but seeks its prey consisting of fishes, mol- 

 luscs, and crustaceans round the edges. The young, generally one, 

 sometimes two, seldom three, are born in March, and are a fortnight 

 or three weeks before they take to the water. This is the seal of 

 the Atlantic trade the earless one that yields the oil and the hairy 

 skins that are made into leather. It is also found in the Pacific, but 

 there it is left in peace, the seal of the Pacific trade being the eared 

 species that yields the furry skins that are made into jackets. 



Phoc. Plate xxiv. CETACEA. 



65. communis, PORPOISE. Black without patches above; tail black, 

 flippers black ; dorsal low. 



The Porpoise, that is the pig-fish, is our best-known dolphin, and is 

 frequently seen and caught off our coasts, and occasionally up several 

 of our largest rivers. It has a short, broad, tapering snout, beyond 

 which the lower jaw slightly projects. In each jaw all along there are 

 from sixteen to twenty-six pairs of small, spatulate teeth, which broaden 

 from the narrow bases by which they rise from the gum. The low 

 dorsal fin begins in the centre of the back and is triangular in shape, 

 and frequently has a row of tubercles on its straight fore-edge ; its 



