CARNIVORA. 607 



cus rosmarus}. The chief peculiarity by which the Walrus is 

 distinguished from the true Seals is found in the dentition. 

 According to Owen, there are six incisors in the upper jaw 

 and four in the lower ; but these are only present in the young 

 animal, and soon disappear, with the exception of the outer- 

 most pair of upper incisors. The upper canines are enor- 

 mously developed, growing from persistent pulps, and consti- 

 tuting two large pointed tusks, which attain a length of over 

 fifteen inches (fig. 261). The direction of the tusks is down- 

 wards and slightly outwards, and they project considerably 

 below the chin. The adult animal has usually three simple 



Fig. 261. Skull of the Walrus (Trichecus rosmarus, after Owen). 

 i Tusk-like upper canines. 



molars with flat crowns behind the tusks in the upper jaw ; and 

 four similar teeth on each side of the lower jaw ; but the first 

 of these has been regarded as a lower canine. The upper lip 

 has many pellucid bristles as large as a straw in thickness. In 

 the adult the incisors are obsolete, except the lateral pair in 

 the upper jaw. Unlike the Seals, the Walrus is not Poly- 

 gamous. 



Except as regards its dentition, the Walrus agrees in all 

 essential respects with the Seals. It is a large and heavy 

 animal, attaining a length of from ten to fifteen feet or up- 

 wards. The body is covered with short brownish or yellowish 



