666 MR. J. W. CLARK ON EARED SEALS. [Dec. 7, 
any other two of the series. In the lower jaw the molars are similar 
in form to those in the upper. The first is extremely diminutive, 
the second larger, and the last three larger still and of equal size. 
All have an anterior cusp, inereasing progressively from the first to 
the last, and a more distinct internal cingulum than in the upper 
jew. The upper canines are moderate in size ; and there is no appre- 
ciable difference between the sexes. Those of the lower jaw are 
much laterally compressed, and have a sharp cutting-edge on their 
inner surface. When the jaws are closed, the lower molars fall be- 
Fig. 6. 
Otaria forsteri, right ear. 
tween, and a little behind, the upper; and the lower canines fit 
exactly into a deep indentation formed in the preemaxilla, and pro- 
ject backwards 2 inch beyond and behind the root of the exserted 
portion of the outermost incisor. These last, as usual in the Ota- 
ride, are very large ; the four middle ones diminutive and of equal 
size. In the lower jaw, the two outermost incisors are somewhat 
larger than the two inner (Plate LXXII. fig. 2). 
In both specimens, the anterior portion of the palate is much 
hollowed out, while the posterior is nearly flat, with its hinder edge 
bounded by a sharp ridge, which is continued up to the pterygoids 
(fig.7, a). These are unusually thin and diminutive plates of bone, 
with small, outwardly curved “hamuli.” The pterygoid plate of the 
alisphenoid (4) is extremely strong and broad, divided into two mas- 
sive pillars of bone, containing the alisphenoid canal (c) between them. 
The innermost of these pillars projects furthest forwards to articulate 
with the palatine and pterygoid, while the outermost receives an 
equally massive process of the palatine, which projects outwards 
and backwards to articulate with it. I observe this construction 
in the two skulls from New Zealand, and in the four from Amster- 
dam Island ; but I have not found it in any other species of Otaria. 
In most, the pterygoid extends much further back, even articulating 
with the basisphenoid ; and the processes of the alisphenoid are by 
no means so massive. The hinder edge of the palate is nearly the 
same in shape in both specimens ; only it is slightly narrower in the 
female. 
The mastoid portion of the periotic is produced at its posterior 
edge into a high ridge or knob. The shape of this differs slightly 
in the two specimens; but the general character is the same. 
