Page:Popular Science Monthly Volume 36.djvu/401

This page has been proofread, but needs to be validated.
BIRDS WITH TEETH.
387

ornis means "fish-bird." The fossil remains from which Hesperornis and Ichthyornis have been described are exhibited in the Museum of Yale College, in New Haven.

A long time, a whole geological period, before Hesperornis and Ichthyornis were enjoying life and eating fish on the vast Cretaceous Fig. 5.—Cervical Vertebra of Ichthyornis dispar, x 2. ocean of the western United States, there was on the other side of the Atlantic, at about the site of the town of Solenhofen, in Bavaria, a lake or marine gulf in a protected situation, with very quiet waters. The lime carried by the rivers into this gulf was deposited at the bottom, in an exceedingly uniform and undisturbed manner, as a very fine sediment. At present, after millions of years, the gulf is dried up and the sediment has been hardened to a limestone, the grain of which is unusually small and regular. In fact, no limestone in any country

Fig. 6. Archæopteryx macroura (Berlin specimen).