CHAP. XIV SKELETON OF SEAL 
where, however, it is the 
milk dentition that is 
most pronounced, the 
“permanent” being 
feeble and very early 
shed. But the dentition 
of the Pinnipedes_pre- 
sents other lkenesses to 
the Cetacea, which are, 
it must be remembered, 
regarded by some as a 
modification of the Carni- 
vorous stock, in which 
case, of course, the like- 
nesses may be genetic 
rather ‘than due to 
adaptation in the two 
cases. There is a dis- 
tinct tendency towards a 
homodont series, the 
grinding teeth being 
often very simple, and 
the very distinct carnas- 
sial tooth of many terres- 
trial Carnivores being 
absent. Finally, the 
number of the back teeth 
shows some signs of being 
on the increase; and 
Professor Kiikenthal has 
found that this increase 
is due to the division of 
existing teeth. Here is 
a point of likeness to the 
many teeth of the typical 
Toothed Whales. Dr. 
Nehring found in several 
examples of Halichoerus 
grypus the normal five 
back teeth increased to 
447 
(After de Blainville. ) 
Phoca vitulina. 
Skeleton of Seal. 
QO 
Fr 
