60 The American Toothed-birds 



in the neck is not known, but from the large number found it is presumed that 

 they were numerous, and that the neck was relatively long and slender. The 

 undoubted strong power of flight enjoyed by Ichthyornis is well indicated by 

 the shoulder girdle and wings, these conforming strictly to the type seen in 

 strongly keeled living oirds, and as has been said, "might have been used by some 

 existing birds with strong powers of flight." The legs and feet are of small size 

 and present no particular features that may not be observed in modern flying 

 birds. The following account of the probable mode of life and habits of Ich- 

 thyornis is from Marsh, the original describer of the bird: "The sharp cutting 

 teeth of Ichthyornis prove, beyond a doubt, that it was carnivorous; its great 

 power of flight, long jaws, and its recurved teeth suggest, moreover, that it cap- 

 tured its prey alive. Its food was probably fishes, as their remains are found in 

 great abundance mingled with those of Ichthyornis. These fossils occur in the 

 bed of the old Cretaceous ocean in which Hesperornis swam. Both of these 

 birds were clearly aquatic in habit, as shown by various points in their structure, 

 and the conditions under which their remains were deposited. In many respects, 

 Ichthyornis probably resembled the modern Terns in its mode of life. The 

 powerful feet and wings suggest similar habits in flight and rest." 



The affinities of Ichthyornis are almost as much in question as those of Hes- 

 perornis. By some it is regarded as being nearest to the Terns and especially 

 the Skimmers, by others it is relegated to the vicinity of the Storks and Plovers, 

 while still others would place it between the Ducks and Accipitres. The truth 

 of the matter is its structure is still too imperfectly known to venture a positive 

 opinion, and even if we were familiar with all the details of its anatomy, it is 

 probable that its direct relationship with modern birds would still be as difficult 

 to establish, for it appears to have belonged, together with its allies, the other 

 Toothed-birds, to a group that represents one link in the chain of succession 

 between reptiles and present birds. 



