RULERS OF THE ANCIENT SEAS 55 



Hesperornis (see page 83), while over the 

 waters flew pterodactyls, with a spread of 

 wing of twenty feet, largest of all flying 

 creatures ; and, not improbably — nay, very 

 probably — fish-eaters, too ; and when each and 

 all of these were seeking their dinners, there 

 were troublous times for the small fry in that 

 old Kansan sea. 



And then there came a change ; to the 

 south, to the west, to the north, the land was 

 imperceptibly but surely rising, perhaps only 

 an inch or two in a century, but still rising, 

 until " The Ocean in which flourished this 

 abundant and vigorous life was at last com- 

 pletely inclosed on the west by elevations of 

 sea-bottom, so that it only communicated with 

 the Atlantic and Pacific at the Gulf of Mexico 

 and the Arctic Sea." 



The continued elevation of both eastern and 

 western shores contracted its area, and when 

 ridges of the sea-bottom reached the surface, 

 forming long, low bars, parts of the water-area 

 were included, and connection with salt-water 

 prevented. Thus were the living beings im- 

 prisoned and subjected to many new risks to 



