Page:Popular Science Monthly Volume 10.djvu/228

216 country the development of cretaceous rocks is enormous; the conditions 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 conception. By his kindness, I am enabled to place before you a restoration of one of these extraordinary birds, every part of which can be thoroughly



justified. The remains exist in the greatest beauty in his collection. This Hesperornis stood about six feet high, and in a great many respects is astonishingly like an existing diver or grebe, so like