LIFE AND WORKS OF COPE. XVll 



Fossil Fishes. 



In 1876 Huxley accepted Cope's separation of the Holo- 

 cephali from the Selachii, and these five groups of living 

 fishes stand as the major classification of the present day, 

 which now rests upon the structure of the fins and of the 

 skull, owing chiefly to tlie labors of Owen, Huxley, and 

 Cope. Cope's interest in the ancestry of the fishes was 

 naturallj' intensified as he became a more convinced evolu- 

 tionist, and b}' his increasing knowledge of the extinct 

 forms. Here his wide preliminary studies among living 

 types stood him in good stead, and stand as a model of the 

 close relations which should always subsist between zoologi- 

 cal and paleontological research. He was first brought into 

 contact with extinct fishes among the Cretaceous vertebi'ate 

 remains from the New Jersey green sand (1869), and con- 

 tinued among the rich yields of the Green River Tertiary 

 whales (1871-77) belonging to the Lower Eocene. Devonias 

 and Carboniferous or older fishes had long been in the 

 hands of Professor Newberry, the pioneer among the stu- 

 dents of Palaeozoic fishes of North America. Cope's dis- 

 coveries led him rather among the intermediate types of 

 the Permian period. 



In his eager quest of phylogenetic relationships his sys- 

 tematic genius led him always to suggestive and often to 

 permanent results. In fact, the masterly part which Cope 

 has played in the major classification of the fossil, as well 

 as of the recent fishes, may well be gathered from a perusal 

 of the introduction of the three parts already published of 

 the " Catalogue of Fossil Fishes in the British Museum," 

 by Woodward, from which many of the subjoined quota- 

 tions are taken. 



In 1884 he proposed a new subclass of the Selachii, 

 namely the Ichthyotomi, founded upon the Permian genus 

 Diplodus, and subsequently enriched by his discovery of 

 Didymodus. Of these Woodward says: "In discuss- 



