36 EDWARD A. WILSON. 



One would have no doubt, judging merely from its outward appearance, that it 

 had some need for a far greater agility than Weddell's Seal, and this is shown when 

 the animal is disturbed, first in attack and then in flight. In attacking man or dogs, 

 it rushes forward first with open mouth and a husky roar, and then as quickly makes 

 off for the nearest hole to reach the water. In character, as in appearance, Lobodon is 

 the most active of all the Antarctic seals on land or ice, but probably is inferior 

 to the others in point of speed while under water. It is usually aggressive when 

 disturbed, and, in comparison with Leptonychotes, might certainly be called " neurotic." 



Its progression on ice is far more rapid than that of Weddell's seal, and its 

 movements when alarmed become as nearly as possible quadrupedal ; for while the lithe 

 and active body takes on the motion of a fish, the fore limbs, instead of lying idle along 

 the sides, as in Weddell's Seal, assume an alternating action, exactly as they would in a 

 four-legged beast. The hind limbs, of course, are functionless as legs, and cannot be 

 brought forward as those of the Eared Seals can ; but the rapid movement of Lobodon 

 when thoroughly alarmed, rushing along as it does with head erect in a sinuous, 

 snake-like course, is strongly suggestive of some fairly recent four-legged antecedent. 

 It has, of course, also the characteristic " looper-like " method of progression, in which 

 the body is alternately hitched up and shot forward from the chest and pubes, and 

 this method it has in common with Weddell's Seal. The other mode of pro- 

 gression seems peculiar to itself. In the water it is naturally more active still, and 

 this activity is probably needful to it, more for escaping from its arch-enemy, the 

 Killer Whale, than for procuring food. 



As Captain Barrett Hamilton has pointed out, the long, pig-like snout and the 

 peculiar character of its teeth, which close upon one another to form a sieve, have both 

 to do with its method of capturing the crustaceans (mainly Euphausise} upon which 

 it feeds. Either at the bottom of shallow seas, or along the " foot " or submerged 

 ledges of bergs and floes, it stirs up both mud and grit and gravel, taking these in 

 freely with the crustaceans that are stirred up with them. The arrangement of the 

 cusps in the teeth of both jaws, then coming into play, allows the water to drain out 

 before the remaining contents of the mouth are swallowed. This development of 

 cusps in the teeth of the Lobodon is probably a more perfect adaptation to this purpose 

 than in any other mammal, and has been produced at the cost of all usefulness in the 

 teeth as grinders. The grit, however, which forms a fairly constant part of the contents 

 of the stomach and intestines, serves, no doubt, to grind up the shells of the crusta- 

 ceans, and in this way the necessity for grinders is completely obviated. 



In a few rare cases there is seen to be some wear, however, in the teeth, and 

 this always in the skulls of the oldest seals. Such wear is not easily accounted for, 

 but may follow, I think, from some change of habit or of diet in old age, perhaps, as 

 in Weddell's Seal, from opening ice-holes in a secluded bay, or from changing to a 

 seaweed diet, as above suggested. The delicate nature of the cusps, one might 

 think, would lead to frequent damage, but this is not the case ; and though it is 



