VERTEBRATA. 835 
ber”) underneath; there are no clavicles; the hind limbs 
are wanting, and the front pair changed to paddles; the 
tail expands into a powerful, horizontal fin; neck and ears 
are apparently wanting; the eyes small, with only two lids; 
the nostrils (“ blow-holes”)—double in the Whale, single 
in the Porpoise—are on the top of the head. All are car- 
nivorous, and essentially marine, a few Dolphins only be- 
ing found in the great rivers. In the Whalebone Whales, 
the teeth are absorbed, and disappear before birth, and 
their place is supplied by horny “baleen” plates. “The 
= ; r 
| syn 
Na\\i\h 
Fig. 332.—Greenland Whale (Balena mysticetus). North Atlantic. 
