110 



A single skull from a half-grown specimen. 



This skull is very like that of A. delalandii, but differs consider- 

 ably in the form of the front edge of the hinder palatine aperture : 

 the outer cutting-teeth and the canines are moderately slender, and 

 similar in form ; but the latter are much the larger. 



Arctocephalus lobatus. 



Arctocephalus lobatus, Gray, Cat. Phocidae B.M. p. 44. 



Face moderately elongate ; palate deeply concave, narrowed be- 

 hind, hinder aperture with a semicircular front edge ; lower jaw 

 rather short, strong. 



Hab. Australia, Port Essington. Houtman's Abrolhos. 



The canines are very large and strong ; the outer upper cutting- 

 teeth are large and compressed- 



Arctocephalus gilliespii. 



Otaria gilliespii, Macbain, Rep. Phys. Soc. Edinb. 1858. 

 The face much elongated ; palate slightly concave, front edge of 

 the hinder aperture ovate ; lower jaw elongate, strong. 

 Hab. California. 



We have a cast of the original skull described by Dr. Macbain, 

 now in the Museum of the College of Surgeons, Edinburgh, from 

 which the figure (PI. LXX.) is taken. - 



The species is at once known by the length of the face : that is, 

 in all the skulls of the genus we have, a line drawn across the palate 

 at the front edge of the zygomatic arch leaves one-third of the 

 palate behind the line, and two-thirds in front of it ; while in this 

 species it leaves only one-fourth behind, and very nearly three-fourths 

 in front of the line. 



The skull has only four grinders on each side in the upper jaw, 

 but one has evidently fallen out in front of the series and one be- 

 hind ; but the fifth grinder of the complete series, which is usually 

 in a line with the front edge of the zygomatic opening, is in this 

 species rather in front of it. 



The Eared Seals (Arctocephali) have been divided into Fur- and 

 Hair- (Eared) Seals by the sealers. A. hookeri and A. lobatus are 

 called Hair Seals, because they are destitute of any under-fur : but 

 this appears to be the case only with the older specimens ; for the 

 young of A. lobatus is said to be covered with soft fur, which falls 

 off when the next coat of hair is developed. The under-fur is well 

 developed in the adult specimens of A. ursinus and A. delalandii and 

 the half-grown specimen of A. nigrescens, and entirely absent in the 

 adult A. hookeri and half-grown A. lobatus in the Museum Col- 

 lection. 



