132 



CARNIVORES. 



HIND-FLIPPERS OF HINGED SEAL— OPEN (a) AND CLOSED (B). 



incisor teeth is variable in the different groups ; but there are constantly five pairs 

 of cheek-teeth in each jaw, of which the first four belong to the premolar series. 



In all the species the under-surfaces 

 of both the fore and hind-feet are 

 covered with hair ; while the fur 

 clothing the body is invariably 

 stiff and devoid of any woolly 

 under-fur. 



The true seals form a much 

 less homogeneous group than the 

 eared seals, and are arranged under 

 several distinct genera; the total 

 number of species being about 

 sixteen or seventeen, although there 

 is still a certain amount of doubt in 

 some cases as to whether some forms 

 should be regarded merely as local 

 races or as distinct species. The 

 greater number of the genera have 

 but a single species each, and in 

 only one of the genera does the 

 number of species exceed two. 

 Distribution and True seals occur along the shores of the temperate and colder 



Habits. portions of the globe ; but the greater number are found in the 

 Northern Hemisphere. Moreover, with the exception of the elephant-seals, the seals 

 of the Northern Hemisphere belong to genera distinct from those inhabiting the 

 Southern Hemisphere ; and the whole of the Arctic species are generically distinct 

 from those of the Antarctic regions. Nearly the whole of the true seals are 

 characterised by their strongly-developed social instincts and their extraordinary 

 affection for their young. In disposition they are, as a rule, gentle and submissive, 

 offering no resistance when attacked by man ; although the crested seal of the 

 North Atlantic is an exception in this respect. Many of the species are accustomed 

 to assemble in large flocks during the breeding-season, while others are gregarious 

 at ;ill periods of the year. It is, however, only the elephant-seals that resemble the 

 eared seals in passing a period of several weeks, during the breeding-season, entirely 

 on land, and without partaking of any kind of food. As a rule there is but a single 

 young one produced at a birth, and there is never more than a pair. All the seals 

 are in the habit of spending a large portion of their time basking in the sun on 

 sandy beaches or ice-floes. 



Their food, of which a large quantity is necessary, consists chiefly of fish, but 

 also comprises crustaceans and molluscs ; and most of the species, like the eared 

 seals, are in the habit of swallowing a number of pebbles. 



As may be at once seen from the total absence of external ears and the 

 structure of the hind-limbs, these seals are more specialised creatures than the eared 

 seals, and are thus more completely adapted for an aquatic life. This is especially 

 shown by the long period these animals can remain under water without coming 



