1^ 



AKTICLE VII. 



(Plates XVII and XVIII.) 



THE OSTEOLOGY OF ELOTHERIUM. 



BY WY B". &COTT. 



(INVESTIGATION MADE UNDER A GRANT PROM THE ELIZABETH THOMPSON FUND OP THE A. A. A. S.) 



Read before the American Philosophical Society, February 4, 1898. 



Elotherium is one of the many genera of fossil mammals concerning which the 

 growth of onr knowledge has been exceedingly slow, and only of late has it become prac- 

 ticable to give a complete account of its bony structure. The genus was named in 1847 

 by Pomel ('47 a, b) and shortly afterward renamed Entelodon by Aymard ('48) from a 

 better specimen, but for several years only the dentition was known and that imperfectly. 

 In 1850, Leidy ('50, p. 90) described the first American species, but, not suspecting its 

 generic identity with the European forms, be at first referred it to a new genus, ArcJiceo- 

 therium. Leidy's material enabled him to give a fairly complete account of the skull. 

 Kowalevsky, in 1876, described an imperfect skull found in France and he further 

 showed that the feet were didactyl, a very unexpected fact in view of the pig-like char- 

 acter of the dentition. In this country Profs. Marsh and Cope have added materially to 

 our knowledge of this remarkable animal (Marsh, '78, '93, '94 ; Cope, '79) and the 

 former has published a restoration of one of the species. In spite, however, of this list 

 of workers who have, from time to time, occupied themselves with the study of Elothe- 

 rium, much still remains to be learned regarding its structure, and its phylogenetic rela- 

 tionships are even more obscure. 



In the summer of 1894, Mr. H. F. Wells discovered in the White River Bad Lands 

 of South Dakota certain bones, which, with the expenditure of infinite pains and skill. 

 were excavated from the rock by Mr. J. B. Hatcher, and which proved to be a most 

 remarkably complete skeleton of Elotherium. This beautiful specimen (Princeton Mu- 

 seum, No. 10885,) formed the subject of a preliminary communication which I made to 

 the third International Zoological Congress, at Leyden (Scott, '96), and will be more fully 

 described in the following pages. Except for a single thoracic vertebra (and perhaps a 



