SEA-SERPENTS. 139 



been of the greatest service in completing our knowledge of this 

 strange group of saurians. In the American Cretaceous seas 

 they ruled supreme, as their numbers, size, and carnivorous habits 

 enabled them easily to vanquish all rivals. Probably some of 

 them were seventy-five feet in length, the smallest being ten or 

 twelve feet long. In the inland Cretaceous sea from which the 

 Rocky Mountains were beginning to emerge, these ancient sea- 

 serpents abounded; and many were entombed in its muddy 

 deposits. On one occasion, as Professor Marsh rode through a 

 valley washed out of this old ocean bed, he observed 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 individuals. 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 Professor Cope of Pennsylvania University, who 

 has made a special study of this group of extinct saurians, fifty- 

 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 

 considerable speed. Like snakes, they were furnished with four 

 rows of formidable teeth on the roof of the mouth, which served 

 admirably for seizing their prey. 



But the most remarkable feature in these creatures was the 

 arrangement for permitting them to swallow their prey whole, in 

 the manner of snakes. Thus each half of the lower jaw was 

 articulated at a point nearly midway between the ear and the 

 chin, so as to greatly widen the space between the jaws, and 



