45 



land ; and that many kinds of fishes formed its food is shown by the teeth 

 and scales found in the position of its stomach. 



A second species of somewhat similar character and habits differed very 

 mnch in some points of structure. The neck was drawn out to a wonderful 

 degree of attenuation, while the tail was relatively very stout, more so, indeed, 

 than in tlie Elasmosaurus, as though to balance the anterior regions while 

 occupied in various actions; e. g., while capturing its food. This was a pow- 

 erful swimmer, its paddles measuring four feet in length, with an expanse, 

 therefore, of about eleven feet. It is known as Polycotylus latipinnis, Cope. 



The two species just described formed a small representation, in our great 

 interior sea, of an order which swarmed, at the same time or near it, over the 

 gulfs and bays of old Europe. There they abounded twenty to one. Per- 

 haps one reason for this was the almost entire absence of the real rulers of 

 the waters of ancient America, viz, the Pythonomorphs. These sea-serpents — 

 for such they were — embrace more than half the species found in the lime- 

 stone-rocks in Kansas, and abound in those of New Jersey and Alaba-na. 

 Only four have been seen as yet in Europe. 



Researches into their structure have shown that they were of wonder- 

 ful elongation of form, especially of tail; that their heads were large, flat, 

 and conic, with eyes directed partly upward ; that they were furnished with 

 two pairs of paddles like the flippers of a wiiale, attached by short wide 

 peduncles to the body. With these flippers and the eel-Hke strokes of their 

 flattened tail, they swam, some with less, others with greater speed. They 

 were furnished, like snakes, with four rows of formidable teeth on the roof of 

 the mouth. Though these were not designed for mastication, and, without 

 paws for grasping, could have been little used for cutting, as weapons for 

 seizing their prey they were very formidable. And here we have to consider 

 a peculiarity of these creatures, in which they are unique among animals. 

 Swallowing their prey entire like snakes, they were without that wonderful 

 expansibility of throat due in the latter to an arrangement of levers support- 

 ing the lower jaw. Instead of this, each half of that jaw was articulated or 

 jointed at a point nearly midway between the ear and the chin. This was of 

 the ball-and-socket type,and enabled the jaw to make an angle outward, and thus 

 widen by much the space inclosed between it and its fellow. The arrangement 

 may be easily imitated by directing the arms forward, with the elbows turned 

 outward, and the hands placed near together. The ends of these bones were 



