Abstract
1. Introductory.—The fragmentary evidence attesting the presence of former tenants of our globe is just sufficiently tantalizing to permit of glimpses of bygone forms to be evoked; and what is lacking in the relics themselves is supplied by the imagination or reasoned out by the aid of existing forms. Palæontology, in truth, is based as yet on a narrow but solid foundation of fact, propped up by much that is uncertain or unstable, which future time must test, try,—accept, or reject. For this reason all adventitious drapery thrown around the remnants of the departed requires to undergo a close scrutiny of its genuineness; and no seeming fittingness can save it from the ruth- less hands of succeeding inquirers should any counterfeit be detected.