94 FLATTENED SHARKS 
The body form of the Skate (Fig. 101) has become ~~ 
admirably adapted to bottom living; it is exceedingly 
flattened anteriorly, its head and trunk and paired fins 3 
fusing so perfectly that from the surface view one could — 
not define their limits; the tail region, on the other hand, — 
has dwindled away to rod-like or whip-like proporieaaay 
Fig. 101. — The barn-door skate, Raja levis, Mitch, g. X }. (After GOODE 
in U.S. F.C.) 
In the process of flattening, the gill openings take their 
appearance early in the ventral side of the body, and the 
pectoral fins, enlarging rapidly, press closely forward at — 
the side of the flattened head, fusing with its tissues. 
Motion is now accomplished by the gentle undulation 
of the long horizontal fin margin: and the enlarged | 
