138 NA T URE-STUD Y RE VIE W [16 :4— April, 1920 



prominent ornithological writers, and to let the world have the 

 result in printed form. 



It is truly an interesting sight to observe a single Black Skimmer 

 when in pursuit of its food, which consists of certain marine aquatic 

 species that it captures with its curious bill as it skims, in gentle 

 flight, over the surface of the sea or over the smoother waters of 

 bays and coast-inlets. I shall never forget how beautiful they 

 appeared when thus engaged along the shores of the sandy cays of 

 Florida — especially at sunrise or sunset, when their black and 

 N white forms were contrasted with the deep blue shades of the water. 

 One can easily imagine any of the long-extinct birds of the genus 

 Ichthyornis similarly engaged, as they skimmed over the ancient 

 cretaceous lakes or other waters of the "Kansas beds." Marsh 

 compared the fossil skeletons of these curious birds of a million or 

 more years ago with those of a modern tern; but as it was quite 

 evident that the teeth in the jaws of an Ichthysaurus were intended 

 to seize its prey with as it skimmed over the surface of the water, 

 just as our Black v^kimmers do to-day over existing seas, Ichthyornis 

 victor, for example, might be a nearer relative of our Black Skim- 

 mer than it was to a tern, as Professor Marsh had supposed. I 

 therefore instituted, some time ago, a comparison of the skeletons 

 of the several forms, which demonstrated the fact that I was cor- 

 rect in this matter. Cur Skimmer, however, has no teeth in its 

 bill, any more than has a Loon, which latter is a descendant of a 

 coexistent species of the Ichthyornis — that is to say, the various 

 species of Hesperornis. 



I am indebted to Mr. Edward J. Court, of Washington, D. C, 

 for the loan of eggs of our Black Skimmer; these I have photo- 

 graphed, and the reader will find them reproduced in the plate 

 illustration 2 of the present article. They may be slightly smaller 

 than the originals, which were each of an oval form, with a ground 

 color of white, over which we find blotches of black or umber brow 

 of various sizes, with sometimes dashes of a purplish tint. They 

 are laid on sand bars and formerly in great numbers ; and Wilson 

 states that ' ' the nest is a mere hollow, formed in the sand, without 

 any other materials. The female lays three eggs, almost exactly 

 oval, of a clear white, marked with large, round spots of brownish 

 black, and intermixed with others of pale Indian ink. These eggs 

 measure one inch and three-quarters, by one inch and a quarter. 

 Half a bushel and more of eggs has sometimes been collected from 



