132 CARNIVORES. 
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. 








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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 stilla certain amount of doubt in 





some cases as to whether some forms 
should be regarded merely as local 
races or as distinet species. The 
greater nuinber of the genera have 


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but a single s yeC1eS each and in 
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HIND-FLIPPERS OF RINGED SEAL—OPEN (A) AND CLOSED (B). 
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 all 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, hke 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 
