24 HANB-MSI OF SEALS, M0E8ES, 



The lower jaw is short and strong, the lower margin, from the su- 

 ture to the angle of the gonyx, is about as long as the extent to which 

 the jaws are separated from one another at the angle ; the outUne of 

 the space between the lower margins is half-ohlong — that is to say, 

 the front is rounded and the sides rather bowed out. The front 

 end of the lower jaw of the young and of some of the old specimens 

 is swollen, thick, and broad, evidently to afford room for the deve- 

 lopment of the lower canines, and are doubtless the jaws of the 

 males, which have very large canine teeth. The lower edge of the 

 lower jaw of the large old skulls much bent out and expanded, 

 giving them quite a different appearance from that of the skulls of 

 the younger Sea-lions. 



The front part of the lower jaw of two skulls of evidently young 

 .specimens, which, from the small size of their canines, are doubtless 

 those of young females, is much less developed, with flattened sides. 

 They have the same short jaws and same form of the opening 

 between the lower edge as the males. 



The width of the four middle cutting-teeth of the upper jaw in 

 the skull of the young Sea-lion is about | inch, and they occupy the 

 same width in most adult skulls. 



The outer cutting-teeth on each side seem to enlarge during Kfe, 

 and with the sex probably of the animal. In a skull 8 inches 

 long the canines are Ig inch apart, measured from the outside, 

 whereas in an adult male skull 14 inches long they are 2| or 2|- 

 inches apart. The canine teeth keep continually growing. Thus, 

 in a young male rather more than 8^ inches long they are 1| 

 inch apart, whereas in an adult male 14 inches long they are nearly 

 5 inches apart. 



The skuUs of the younger animals have the grinders in the nor- 

 mal position with relation to the front part of the zygomatic arch — 

 that is to say, the fifth is partly and the sixth entirely behind the 

 hinder edge of the front of the zygomatic arch ; but this part of the 

 arch expands in the very old skulls, especially of males, so that the 

 sixth upper grinder appears to alter its place, and be partially or 

 completely before the hinder edge of this part. Sometimes this 

 tooth, on the two sides of the jaw, diifers in this respect, one being 

 partially and the other entirely before the hinder edge of the front 

 of the zygomatic arch. 



This animal is the " Sea-lion " of Cook and Forster, Byron, 

 and other voyages in the South Seas. It is the " Lion marin " of 

 Butfon and Cuvier, the Otaria molossina of Lesson's ' Voyage of the 

 Coquille,' t. iii. ; the Otaria hookeri of Murie, P. Z. 8. 1867, p. 243 ; 

 the Sea-bear of the ' Illustrated London News.' 



The skull of Byron's specimen is in the Museum of the Royal 

 College of Surgeons, and the skull of Otaria molossina of Lesson is 

 in the Museum of Paris. 



The skull is figured in Cuvier, Oss. Foss. v. p. 222, t. xviii. fio'. 4, 

 as lAoii marin ; in Blainville's ' Osteographie,' t. vi. and t. ix. as 

 P. leonina ; in Frederic Cuvier, Mem. Mus. xi. p. 208, t. xv. fig. 2, as 

 the type of his genus " Phiti/rhynque ;'' and the young skull is figured 



