Fossil Birds from the Green River Deposits of eastern Utah

Plates XXXVI-XXXVIL) During field-work for the Carnegie Museum in the season of 1923, Messrs. Earl Douglass and LeRoy Kay discovered on White River in Utah about two miles from the Colorado line a deposit, in which were a considerable number of bones of birds.These specimens, whichwere distributed over the surface of a large slab of hard sandstone, came from the lowest levels of the Green River Formation in the Eocene.Though a considerable number of individual bones are represented, the majority are fragments of ribs, radii, or similar bones, which offer no characters for identification.Among them there are a few bones from other parts of the body, all more or less crushed, but in condition to permit definite determination.From these I have described three species, which are characterized in the following pages.The three species herein named seem to have no definite connection with birds which have been previously described from the Eocene, and distinctly add to our small fund of knowledge of the bird-life of that remote period.All three seem to have been adapted to life on or around water, and appear allied to two groups, the Auks and the Avocets, among modern birds.To enable proper understanding of their characters, study of these specimens has been prolonged over a period of months, during which the fossils have been compared with large series of modern forms in the collections of the United States National Museum.The specimens were all disassociated, so that correlation of different parts of the skeleton has come through a process of analogy.For the privilege of examining this material I am indebted to Dr.