218 EXTINCT MONSTERS 



indicates that its wings were "rudimentary," and quite useless 

 either for flying or swimming (see Fig. 81). Modern penguins 

 use their wings with great effect while swimming under water, 

 but the Hesperornis was compensated for the want of wings by its 

 broad tail, which was much expanded horizontally, and doubtless 

 served as an organ of propulsion in diving. (The tail in our 

 restoration is too small.) 



The brain was diminutive, and very like that of a reptile. It 

 is impossible, in the absence of feathers, to say exactly what 

 appearance the skin of this bird presented, but in the restoration, 

 Plate XXXIV., our artist has to some extent taken a modern diver 

 as his model. The skeleton of this bird presents several interesting 

 points of resemblance with reptiles ; but it will not be necessary 

 to enter into anatomical details here. The remains were dis- 

 covered by Professor Marsh, in certain marine Cretaceous strata 

 along the eastern slope of the Eocky Mountains, which have 

 also yielded mosasauroid reptiles, Pliosaurs, and Pterodactyls. 

 The valuable specimens on which Professor Marsh's descriptions 

 are based were not procured without considerable trouble and 

 hardship. His exploring parties in the plains of Kansas and 

 Colorado suffered, at one time, from extreme heat, causing 

 sunstroke and fever, by which the guides and explorers alike 

 were weakened and discouraged; at other times, from extreme 

 cold, to say nothing of the danger from hostile Indians. But 

 fortunately, the latter enemies to science were kept in check by 

 escorts of soldiers. 



Hesperornis, as we have seen, was an admirable diver; while 

 the long neck, with its capabilities of rapid flexure, and the long 

 slender jaws armed with sharp recurved teeth, formed together a 

 perfect instrument for the capture and retention of the most agile 

 fish. As the lower jaws were united in front only by cartilage, as 



