68 



ANIMALS OF THE PAST 



University Museum, at New Haven. The United States Na- 

 tional Museum at Washington has a fine mounted skeleton of 

 Hesperornis, the American Museum of Natural History another, 

 and the State University of Kansas, at Lawrence, has the ex- 

 ample showing the impressions of feathers. 



For scientific descriptions of these birds the reader is referred 

 to Owen's paper "On the Archwopteryx of von Meyer, with a 

 Description of the Fossil Remains, etc.," in the " Transactions of 

 the Philosophical Society of London for 1863," page 33, and 

 "Odontornithes, a Monograph of the Extinct Toothed Birds of 

 North America" by 0. C. Marsh. Much popular and scientific 

 information concerning the early birds is to be found in Newton's 

 "Dictionary of Birds," and " The Story of Bird Life," by W. P. 

 Pycraft; the "Structure and Life of Birds," by F. W. Headley; 

 " The Story of the Birds" by J. Newton Baskett. ~ 



Mr. Beebe's theories of the beginning of flight may be found 

 in Zoologica; Vol. II, No. 2, 1915, under the title The Tetrap- 

 teryx Stage in the Ancestry of Birds. 



ARCH^OPTERYX, FS Restored by Pycraft 



