508 CARNIVORES. 



nalones in the upper jaw are intermediate in size between the canines 

 and the middle incisors. 



In the Stenorhynchus leptonyx each molar tooth in both jaws is 

 trilobed, the anterior and posterior accessory lobes curving towards 

 the principal one which is bent slightly backwards ; all the divisions 

 are sharp-pointed, and the crown of each molar thus resembles the 

 trident or fishing-spear ; the two fangs of the first molar in both 

 jaws are connate. In Sten. serridens (PI. 132, fig. 4) the three anterior 

 molars on each side of both jaws are four-lobed, there being one 

 anterior and two posterior accessory lobes ; the remaining posterior 

 molars (true molars) are five-lobed, the principal cusp having one 

 small lobe in front and three developed from its posterior mar- 

 gin ; the summits of the lobes are obtuse, and the posterior 

 ones are recurved like the principal lobe. Sometimes the third 

 molar below has three instead of two posterior accessory lobes. 

 Occasionally, also, the second as well as the first molar above 

 has its fangs connate ; but the essentially duplex nature of the 

 seemingly single fang, which is unfailingly manifested within by 

 the double pulp-cavity, is always outwardly indicated by the 

 median longitudinal opposite indentations of the implanted base. 

 These slight and unessential varieties, presented by the speci- 

 mens of the Saw-toothed Sterrink {Stenorhynchus serridens) brought 

 home by the enterprising Naturalists of Sir J. Ross's Antarctic 

 expedition, accord with the analogous varieties noticed by the best 

 observers of the Seals of our neighbouring seas, as, for example, 

 Nillson.(l) 



The Grey Seal {Halichcerus gryphus) of our own Seas begins, by 

 the extension of the connate condition of the two roots through a 

 greater proportion of the molar series, to manifest a transition to the 



(1) A diligent labourer, in what our plain-speaking German fellow-zoologists call the 

 * Gattungsmacherei' has seized upon the variable mode of implantation of the anterior 

 premolars as ground for the generic distinction of Seals ; and so by the following phrase, 

 " the 1st, 2d and 3d front upper, and the 1st front lower grinder single-rooted, the rest 2 rooted,"{d) 

 my Stenorhynchus serridens is tied as a synonym to the tail of ' Lobodon carcinophaga. Gray.' 

 Not a single additional fact does the writer find to add to those characters which I first pointed 



(a) Zoology of Ross's Antarctic Voyage, Mammalia, p. 2, 4to. 1844. 



