REPTILIA. 
33 
been almost inflexible, and could not have assumed the graceful Cases P, Q. 
curves usually ascribed to it in fanciful restorations. The 
body is barrel-shaped, and its lower face, between the ends 
of the ribs, is strengthened not only by the expanded plates 
of bone which support the paddles, but also by many inter¬ 
vening rows of abdominal ribs. The tail is quite short, and 
is known to have been provided with a small rhomboidal 
D 
