16 



NEBRASKA ORNITHOLOGISTS' UNION 



strong shoulder-girdle and broad ossified sternum, with keel for the at- 

 tachment of the great flying muscles, are the properties of birds of flight, 

 and so are they of rei^tiles of flight. The hollowness of its bones Is 

 paralleled by that of the more active rejDtiles. The vertebrae were 

 biconcave or flat at the ends, as in many reptiles, and not heterocoelous 

 or saddle-shaped, as in the case of birds, and those of the tail, number- 

 ing twenty in all, were lizard-like, not having been atrophied, as in 

 modern birds. The pelvic bones are unconsolidated, which is a char- 

 acter of reptiles and of embryonic birds. The conviction must force 

 Itself upon every honest mind that we have here a mixture of characters. 



Fig. 37 — Archaeopferyx macrnya {UtluHjraphica). H. von Meyer, after Owen. From the 

 lithograpliic limestone of Solenhofen, Bavaria (upper Jurassic), preserved in the 

 British Museum — \ natural size. Showing skeleton with impression of wing and tail 

 feathers. 



