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THE POPULAR SCIENCE MONTHLY 



country the development of cretaceous rocks is enormous; the condi- 

 tions under which the later cretaceous strata have been deposited are 

 highly favorable to the preservation of organic remains, and the 

 researches full of labor and toil, which have been carried on by Prof. 

 Marsh in these Western cretaceous rocks, have rewarded him with 

 the discovery of forms of birds of which we had hitherto no concep- 

 tion. By his kindness, I am enabled to place before you a restoration 

 of one of these extraordinary birds, every part of which can be thor- 



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Fig. 3. Hesperornis Regalis. (Marsh.) 



oughly justified. The remains exist in the greatest beauty in his col- 

 lection. This Hesperornis stood about six feet high, and in a great 

 many respects is astonishingly like an existing diver or grebe, so like 



