SEA-SERPENTS 193 
no less than seven different skeletons of these monsters in sight 
at once! The same authority mentions that the Museum of Yale 
College contains remains of not less than 1400 distinct indi- 
viduals. In some of these the skeleton is nearly if not quite 
complete; so that every part of its structure can be determined 
with almost absolute certainty. 
According to the late Professor Cope of Pennsylvania University, 
who made a special study of this group of extinct saurians, fifty- 
Fic. 69.—Lower tooth of Leiodon. 1. Side view. 2. Profile. 
one species have been discovered in North America, in the States 
of New Jersey, Alabama, Kansas, North Carolina, Mississippi, 
and Nebraska. The same authority has shown that they were 
characterised by a wonderful elongation of form, especially of the 
tail; that their heads were large, flat, and conical in shape, with 
eyes directed partly upward; that they were furnished with two 
pairs of paddles like the flippers of a whale. With these flippers, 
and the eel-like strokes of their flattened tail, they swam with 
O 
