May 7, 1897.] 



SCIENCE. 



709 



of research, which he pursued concurrently 

 to the end of his life ; these must, however, 

 be followed separately to be understood and 

 appreciated. Only for comparatively brief 

 intervals would one line be pursued exclu- 

 sively in order to complete some special 

 memoir, for his marvelous memory appar- 

 ently held and resumed the details of all 

 the others with perfect ease. 



Cope's work in ichthyology would alone 

 have given him high rank among zoologists. 

 In his early papers (1864) he appears as an 

 enthusiastic systematist, studying especially 

 the living forms of Teleosts, making care- 

 ful diagnoses of all types that came into 

 his hands, critically considering the prob- 

 lems of distribution, never casting aside 

 those types whose especial diflBculties had 

 been the stumbling block of earlier writers. 

 Thus he studied successively the fishes of 

 Michigan (1864-65), of Virginia (1868), 

 of the Lesser Antilles (1870), the cyprinids 

 of Pennsylvania (1867), again the fishes of 

 South Carolina (1871), of Alaska (1872), 

 of Montana, those from South America 

 collected by Professor Orton (1872-78), 

 those from the territories collected by the 

 Wheeler Survey, and even not infrequently 

 new forms from Africa and the East Indies. 



Almost from the first he set aside the 

 superficial characters which had been em- 

 ployed in the classification of fishes, sym- 

 pathizing keenly with the morphological 

 spirit in systematic study which Dr. Gill 

 was then showing. A great step in his 

 career was, therefore, his purchase, while 

 abroad, of Professor Hyrtl's private collec- 

 tion of fish skeletons, which gave him 

 nearly a thousand admirable preparations 

 for immediate study. Owen had proposed 

 (1866) the Teleostomi to include the old 

 Ganoids and Teleosts. Before the Ameri- 

 can Philosophical Society, in 1870, and the 

 American Association, in 1871, Cope dem- 



onstrated the law that the primary divisions 

 of the Teleostomi are indicated by their 

 fin structure. This is now the accepted basis 

 of sub-ordinal classification. Besides pro- 

 posing the Adinopteryii, he established the 

 fundamental division (Holocephali, Se- 

 lachii, Dipnoi, Crossopterygii, Actinoptery- 

 gii) of the living fishes into five groups, as 

 they stand at the present day, upon cranial 

 and fin structure. In 1876 Huxley adopted 

 Cope's wide separation of the Holocephali 

 from the Selachii. Fin structure as a tax- 

 onomic motive was uppermost in his mind 

 and undoubtedly served to direct his atten- 

 tion later to the foot structure of land ver- 

 tebrates as of diagnostic value. 



The masterly part Cope continued to play 

 in the major classification of the fishes may 

 be gathered from a perusal of the introduc- 

 tions of Smith Woodward's standard vol- 

 umes ' Catalogue of Fossil Fishes of the 

 British Museum.' In 1884 he proposed a 

 new Elasmobranch subclass, Icthyotomi, from 

 the Permian Diplodus. This order was sub- 

 sequently enriched by his discovery of Didy- 

 modus and is now firmly established to in- 

 clude the pleuracanth and other paleozoic 

 sharks. In 1889 he proposed another great 

 sub-order, the Ostraeodermi, which is also 

 established. 



His interest in the phylogeny of the group 

 was naturally intensified by increasing 

 knowledge of extinct forms, and here his 

 wide studies among living types stood him 

 in good stead, for he was first brought in 

 contact with fishes from the Tertiary and 

 Cretaceous, from the vertebrate remains 

 from the New Jersey Greensand (1869) to 

 the rich yields of the Green river shales 

 (1871-7). The older fishes had long been 

 in the hands of Professor Newberry, the 

 pioneer among the fossil fishes of North 

 America, but his studies came naturally to 

 lead him among the more ancient types in 

 his eager study of phylogeny. Into this diffi- 

 cult field he carried his work always with 



