564 



SCIENCE. 



[N. S. Vol. IX. No. 225. 



work in his entire career. Various futile 

 attempts had been previously made to trace 

 the ancestry of the Modern Horse. Huxley 

 and Kowalewsky in Europe had established 

 the fact that mammals belonging to the 

 equine stem were found in Europe in the 

 early Pliocene and late Miocene, but their 

 attempt to trace the line into any older 

 formations signally failed. Shortly after 

 this Professor Marsh pointed out the equine 

 nature of his Bridger genus Orohippus, and 

 was the first to show that the fossil forms 

 of the American Continent furnished every 

 conceivable link between the small poly- 

 dactyle species of the Eocene and the modern 

 horse. So strong, indeed, is the evidence 

 of this descent that were there no other 

 evidences of evolution to be found among 

 the fossils this would be quite sufficient of 

 itself to establish its truth. In May of this 

 year he published an important paper set- 

 ting forth these discoveries on the ' Fossil 

 Horses in America.' 



In 1875 he published additional discov- 

 eries among the Cretaceous birds, and de- 

 termined for the first time that Hesperornis 

 possessed teeth in both jaws. In the suc- 

 ceeding year a series of important papers 

 appeared, giving the principal characters of 

 the Dinocerata, Tillodontia, Brontotheridse 

 and Coryphodontia. Of this latter group 

 he was the first to point out that they were 

 very closely allied to a genus that was de- 

 scribed by Owen as early as IS^G from a 

 > few fragmentary remains found in the 

 Eocene of Europe, thus giving the first se- 

 cure basis for a comparison of the older 

 Eocene deposits of the two countries. In 

 this year he was elected Vice-President of 

 the American Association for the Advance- 

 ment of Science, and in the following year 

 succeeded to the Presidency of the body. 

 His address as the Vice-President upon the 

 ' Introduction and Succession of Vertebrate 

 Life in America ' is a notable production 

 and shows the wonderful knowledge he 



possessed of the organization of the Verte- 

 brates. 



Some notable discoveries which marked 

 the beginning of his extensive and impor- 

 tant contributions to the knowledge of the 

 extinct reptiles of the group Dinosauria 

 from the Rocky Mountain region were pub- 

 lished early in 1877. From this time on, 

 almost up to the time of his death, one dis- 

 covery after another pertaining to these 

 weird gigantic creatures followed in rapid 

 succession. This subject came to engross 

 his attention more and more, and at the 

 time of his death was the one in which he 

 was the most deeply interested. In 1879 

 the first discovery of fossil Mammals from 

 the Western Mesozoic was announced, and 

 within the next few years a large number of 

 genera and species were added to the list. 

 His contributions to the subject constitute 

 practically all we know of the American 

 Jurassic Mammalia. In 1880 appeared his 

 first important Monograph on the ' Extinct 

 Toothed Birds of North America,' an im- 

 portant and beautifully illusti'ated volume 

 published by the United States Geological 

 Survey. In 1886 followed his second 

 Monograph on the ' Dinocerata, An Extinct 

 Order of Gigantic Mammals,' which served 

 to bring together and present in extended 

 form his manj^ discoveries on this subject, 

 a work which was likewise published by 

 the Government Survey. In 1889 two dis- 

 coveries of more than usual importance were 

 made ; one was the finding of a very exten- 

 sive Cretaceous Mammalian fauna in the 

 Laramie Beds of Wyoming, and the other 

 the discovery of those curious horned Din- 

 osaurs, the Ceratopsia, in the same de- 

 posits. 



It would be impossible to give here even 

 a list of his papers which have contributed 

 so immensely to our knowledge of the ex- 

 tinct Reptilia. It is in this difficult group 

 especially that his splendid knowledge will 

 be so sadly missed, and it will, indeed, be 



