HESPElIOliXITHES :;<>.-, 



The prepubic process is large, but not larger than in certain 

 recent birds, and not so large as in Geococcyx and Tiiuuimx. 



' The femur of Hesperornis is remarkably short and stout, 

 more so than in any known bird, recent or fossil.' The tili/i 

 has an enormous cnemial crest, as in divers, and the patella 

 is a huge bone ; the latter is perforated by a foramen for the 

 ambiens muscle. The feet have four toes. 



Nothing is known about the soft parts of this bird, save 

 the feathers, which have been lately l stated to be quite 

 ostrich-like. But casts of the brain have brought to light 

 the interesting fact that it has smaller cerebral hemispheres 

 than are found in any existing bird. 



It seems clear that, as D'AncY THOMPSON and others have 

 argued, the nearest affinities of Hesperornis are with the 

 Colymbi. That they are more nearly related to the ratites 

 was the opinion of MARSH. The likeness to the ratites, 

 however, seems mainly to be based upon the degenerate 

 structure of the wings in both. The degeneration of the 

 wings, however, has not proceeded along precisely similar 

 lines. Although the angle between the scapula and the 

 coracoid is nearly as open as in the ratites, the two bones 

 have not become ankylosed ; and moreover the clavicles are 

 retained. The fact that of the fore limb only the humerus 

 remains (at least in an ossified condition) may be compared 

 with the fact that in the Dinornithidse traces of the same 

 bone have been met with. On the other hand there are 

 more positive likenesses to the Colymbi, which are not so 

 clearly due to the immediate action of environment. The 

 long and narrow pelvis, and the huge cnemial crest with the 

 relatively enormous patella, are among the more salient points 

 of resemblance. 



The characters in which the Hesperornith.es approach the 

 Colymbi are divided between the two families of the latter 

 group ; in some points Hesperornis is more of a diver ; in 

 others it comes nearer to the grebes. The following table 

 of comparison may help to make its ' mixed ' characters 

 clear : 



1 In a letter to Nature, April 8, 1897, by Prof. MARSH. 



