Dr. J. E. Gray on Sea-hears. 265 



skull of a young Euotaria mgrescens, n. 1013 e, in the British- 

 Museum collection. The front edge of the hinder nostrils is 

 as arched as in that specimen ; the teeth are rather more de- 

 veloped and larger than in our skull ; they have a well-marked 

 central lobe and a distinct small acute tubercle on the front 

 edge of the cingulum. 



The two adult skulls are very like the adult skull of ^. ni- 

 ffrescens, 1013 d, in the British Museum ; but the opening of 

 the internal nostrils is narrower, and their front edge in 

 one is not nearly so angular, and in the other it is rather 

 more arched tlian in either of the other two skulls, showing 

 that the size of the posterior nasal aperture and the form of its 

 front edge vary in difterent specimens of this species. 



The comparison of the young skull with the more adult one 

 shows that the grinders change their position considerably 

 as regards the front edge of the hinder nasal opening. In the 

 young skull of Euotaria nigrescens the hinder end of the tooth- 

 line is very near (not a quarter of an inch from) a line level 

 with the front edge of the internal nasal opening, and the 

 hinder part of the palate in front of the aperture is nearly as 

 broad as the middle of the palate : in the adult skull the 

 hinder end of the tooth-line is a full inch from the front edge 

 of the internal nasal opening, the hinder part of the palate 

 is contracted toward the internal nostril, and the internal 

 nasal opening is lengthened and narrowed ; but the real posi- 

 tion of the teeth, as compared Avith the front part of the 

 zygomatic arch, is little altered, though the form of the palate 

 gives them the appearance of being more changed than they 

 really are. 



These skulls are interesting as showing that Euotaria ni- 

 grescens^ like Otaria leonina and Morunga elepliantina^ are 

 common to the Falkland Islands and the west coast of South 

 America. 



The chief character by which the adult skull of Euotaria 

 nigrescens can be distinguished from the adult skull of Arcto- 

 ceplialus Delalandii is, that the hinder or fifth upper grinder 

 and the penultimate or fourth are placed rather in front of the 

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

 position of the teeth is most distinctive in the skull of the 

 young animal, and loses much of its importance in comparing 

 old skulls together, unless the skulls and teeth are very 

 accurately compared ; and even then the distinction is more 

 imaginary than real. 



The skull from the Cape of Good Hope has been described 

 and figured by Dr. Turner under the name of Arctoeeplialus 

 scMstliyperoes^ in the ' Journal of Anatomy and Physiology,' 



