SEA-LIONS, AND SEA-BEAKS. 



31 



Eumetopias Stelleri, Gray, P. Z. S. 1872, p. 737, fig. 1 (head), figs. 2 & 



3 (skull). 

 Otaria Stelleri, Schlegel, Faun. Japonica, tab. xxii. figs. 5 & 6 (?). 



Japan {A. Adams). 

 1320 c?. Skull, young, short. Palate short, broadly truncated 

 behind. (PI. XXII.) 



Eumetopias elongatus. Gray, P. Z. S. 1873, p. 776, figs. 1 & 2. 

 Japan {A. Adams). 73. 10. 



In the older specimens of Phocarctos elongatus the four middle 

 cutting-teeth occupy three fourths of an inch at their base, but in 

 the young skull they only occupy rather less than five eighths of an 

 inch ; but the difference may be allowed for in the dilatation of the 

 intermaxillary bone during growth. 



The lateral cutting-teeth and the canines greatly increase in size 

 as the animal grows ; whereas the space between the outer edge of 

 the canines is 11 inch in the young, it is 2| inches in the larger 

 specimen, and they are still being enlarged. 



The skull said to have come from Japan is light and thin, and the 

 sutures are still visible. The width at the condyles of the lower 

 jaw is considerably less than the length from the front cutting- teeth 

 to the tubercles on the side of the hinder nasal opening. The 

 grinders have elongated conical rather compressed crowns and a 

 distinct basal coUaret ; the fifth hinder one is more compressed, and 

 only separated from the fourth by a space about as wide as the fifth 

 tooth. This tooth has a compressed and very indistinctly divided 

 base, very unlike the two diverging and unequal lobes of the adult 

 skull. The lower jaw is much dilated in front, and very obliquely 

 truncated and swollen, having a very different appearance from that 

 of the adult animal. The gi-inders are rather elongate-conical, with- 

 out any or only a slight lobe on the front of the collaret, the fifth 

 or hinder grinder, with a smaller more compressed crown, having a 

 lobe on the front and hinder edge. The canines are large, rather 

 compressed, with a sharp cutting-edge on the hinder side ; the outer 

 upper cutting-teeth are large, nearly half the size of the canines ; 

 the crown of the grinders is elongate-conical, all these parts being 

 much more acute and compressed than in the adult skuU, the teeth 

 becoming thicker and more cylindrical with age. 



The skull from Japan is 11 inches long, and 5| inches broad at 

 the condyles of the jaws ; lower jaw 71 inches long. The skuU of 

 the very young is 7| inches long and 4| inches broad. 



I placed this species, when I first described it from a single full- 

 grown skull, in the genus Eumetopias, because it had a space in the 

 place of the fifth upper grinder, as in that genus, pointing out how 

 it differed from Eumetopias Stelleri (P. Z. S. 1872, p. 738) ; but we 

 have since then purchased a small skull of a young animal coming 

 from Japan, and taken by the same person who collected the larger 

 skull ; and it agrees with it in all the more important points, and 

 only differs from it in having a shorter palate and in the form of the 

 internal nostrils (aU characters that I have found to alter with the 



