RATIT,. 



235 



Hesperornis (fig. 143). This bird is known by nearly complete skele- 

 tons. The snout is much elongated, and the premaxilla? are forked con- 

 siderably in their hinder portion. The cranial bones are fused together, 



Fio. 143. 



Hesperornis regalis ; skeleton, one-eighth nat. size. TJ. Cretaceous; Kansas. 



(After Marsh.) 



and exhibit deep supraorbital pits. Casts of the brain-cavity prove it 

 to have been small, and the cerebral hemispheres must have been very 

 little developed. The relations of the vomer are not quite clear, but it is 



