384 Mr. R. Walker on the Skeleton of a Seal 



of the common Seal that there appears to be no peculiarity 

 about any of them deserving of special notice in this place; and 

 some of them will be noticed in the sequel. The dorsal ver- 

 tebrae are chiefly remarkable for the depressed condition of 

 the neural arches, and the total absence of neural spines in 

 all but the first, and perhaps the second vertebra. In these 

 vertebrae the neurapophyses form a series of flattened domes 

 over the central axis ; they are completely coalesced, and project 

 backwards, somewhat lapping over the anterior notch of the 

 contiguous vertebra. In the second vertebra the anterior edge 

 of the middle of the neural arch is exactly on a level with the 

 upper edges of the diapophyses; in its course backwards, it 

 gradually rises, till, at its posterior margin, it is about y^^^ths of 

 an inch higher; in the third, the neural arch, at its posterior 

 extremity, where it is highest, is exactly the same height as the 

 diapophyses; and here the margin is about fths of an inch 

 broad from side to side, and slightly notched in the middle. 

 From this part these arches become gradually lower and lower, 

 till in the tenth vertebra the top of the arch is almost flat, and 

 about an eighth of an inch under the height of the diapophyses. 

 In the eleventh the arch is quite flat, and is exactly at a right 

 angle with the anterior face of the centrum : this, as well as 

 some of the preceding vertebrae, has a round posterior margin, 

 which begins a little behind the zygapophyses ; they have like- 

 wise a small notch on the middle of their posterior edge. From 

 this to the second last dorsal the arches are still flat ; but in the 

 last dorsal and succeeding lumbar they rise high in the middle ; 

 and then the neural spines, although not particularly prominent, 

 are still distinctly developed. From the eleventh dorsal vertebra 

 the round on the posterior margins of the neural arches becomes 

 gradually less as they approach the first lumbar, where the margin 

 is straight across ; after this the margins are slightly concave, 

 but in the posterior lumbar they are notched under the neural 

 spines. The diapophyses are similar in size to those of the 

 common Seal, P. vitulina ; and there are metapophyses feebly 

 developed on the last four dorsal vertebrae. 



I have thus far attempted to describe this Pliocene Seal ; for, 

 although the bones of Seals have been occasionally met with in 

 the upper clay-beds of Scotland and other places, they have 

 heretofore been found in too detached and fragmentary a condi- 

 tion to admit of any description showing their specific identity. 



How far the present Seal agrees with or diff"ers from any of 

 the existing species is the next point of importance to be con- 

 sidered. The broken condition of its cranium, the absence of 

 the characteristic palatal and nasal bones, and the immature 

 state of the specimen, on the one hand, and, on the other, the 



