494 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
A graveyard of whales, such as exists in the Upper Miocene and 
Pliocene bay of Antwerp, is a quite unique phenomenon. 
The sea-cows arose in the Mediterranean region in the Middle 
Eocene. Until the Pliocene they were abundant on the seacoasts of 
Europe. From thence the ancestors of the dugong took their way 
toward the east and those of the manatee toward the west. Thus it 
at once becomes clear why the range of the two living genera of sea- 
cows is so sharply separated, and why such fundamental differences 
exist between the dugong and the manatee. They separated at a very 
early time in the Mediterranean from the main stock of the sea-cows, 
which is now extinct, while the branches continue. 
Let us return again to the whales. “he degeneration of the pelvis 
in the sea-cows which we can follow directly, gives us the means for 
solving the problem of the rudimentary hind 
limbs of the whales. If we compare the pelvis 
of the bowhead or Arctic right whale (fig. 
25) and that of the finback (fig. 26) with 
the pelvis of the oldest sea-cows, the corre- 
spondence becomes at once apparent. In both 
cases the ileum, pubis, and ischium are in 
all respects similarly formed. The obturator 
foramen has disappeared, the acetabulum 
for the femur is no longer functional. The 
ileum is very long, the ischium and _ pubis 
aborted. Most significant, however, is the 
Hie. 24.—Left pelvic bone position of the remains of the pelvis in the 
of the American Mana- i 
tee, Manatus latirostris body of the whalebone whales. ‘The pelvis 
Be nt Ot ee of the Arctic right whale is turned 180°, as 
of the femur. The ileum Compared with that of the finback. The rudi- 
and the pubis are lack- ment of the pelvis of the toothed whales cor- 
ing. 5 ; 
responds also entirely with the forms found 
in the dugong. It follows that the reduction of the pelvis and of the 
hind limbs in both not closely allied groups, the whales and the sea- 
cows, must have proceeded in exactly the same order. 
The example shows in the clearest manner the importance of the 
study of fossil forms, as it is only through a more exact knowledge 
of them that we can properly understand the structure of living 
animals. 
If we turn to the primitive history of the seals, we are forced to say 
that their origin is not yet clear. The most probable supposition is 
that they originated from bears. Paleontology unfortunately leaves 
us in the lurch, as the oldest seals of the Miocene already show all the 
characters of existing seals. But through the multifarious observa- 
tions which at present extend throughout all civilized countries, it 
