As a scientist Marsh possessed in large measure that wide knowledge of comparative anatomy so necessary to the vertebrate paleontologist, and as a consequence was not only able to recognize affinities and classify unerringly, but also to recognize the salient diagnostic features of the form before him and in few words so to describe them as to render the recognition of the species by another worker relatively easy. The publication of hundreds of these specific diagnoses in the Journal constitutes a very large and valuable part of that periodical’s contribution to the advancement of our science. Marsh’s method of indicating forms by so brief a statement leaves much to be done, however, in the way of further description of his types, which in many instances were but partially prepared. Yet another important service which Marsh rendered to science was the restoration of the creatures as a whole, made with the most painstaking care and precision through assembling the drawings of the individual bones. These restorations have become classic, embracing as they did a score or more of forms, of beast, bird, and reptile. They also were published first in the Journal, although they have subsequently been reproduced in text-books and other works the world over. Part of Marsh’s popular reputation, at least, which was second to that of no other American in his line, was due to his skill in attaining publicity, for his papers, of whatever extent, were carefully and methodically sent to correspondents in the uttermost parts of the earth, and thus the Marsh collection has reflected the fame of its maker. _Edward Drinker Cope (1840–1897)._ The third great name in American vertebrate paleontology, that of Edward Drinker Cope, stands out in sharp contrast with the other two, although in the range of his interests he was probably more nearly comparable with Leidy than with Marsh. The beginning of Cope’s scientific labors dates from 1859, the year made famous in the annals of science by the appearance of Darwin’s Origin of Species. It is not surprising, therefore, that matters evolutional should have interested him to the very end of his career. Cope was not merely a paleontologist, but was interested in recent forms, especially the three lower classes of vertebrates, to such an extent that his work therewith is highly authoritative and in some respects epoch-making. Thirty-eight years of almost continual toil were his, and the mere mass of his literary productions is prodigious, especially when one realizes that, unlike those of a writer of fiction, they were based on painstaking research and philosophical thought. The greater part of Cope’s life was spent in or near Philadelphia except for his western explorations, and he is best known as professor of geology and paleontology in the University of Pennsylvania, although he served other institutions as well.