Ammonites, and such small geological fry, were to be found by the thousand in the petrified mud beds of the Cobb region; but it was left to the ingenuity, aided by good fortune, of the foreigner to unearth from the flaking and perishing cliffs of lias some of the earliest and finest specimens of the ichthyo- and plesio-saurus that a past world has yielded to the naturalists.