THE OSTEOLOGY OF ELOTHERIUM. 321 



withers. These spines are figured as having curious expansions at the tips, which arc 

 either absent or much less distinctly shown in the skeleton described in the present paper. 

 (5) The lumbar region is longer and has neural spines which are lower and incline more 

 strongly forward. (6) The conjectural restoration of the presternum is entirely different 

 from the specimen herewith figured. (7) The scapula is relatively shorter and broader, 

 and has a less prominent acromion. (8) The ilium has a shorter neck, expanding more 

 gradually into the anterior plate and with the acetabular border of an entirely different 

 shape. The ischium is much more slender, is more everted and depressed at the posterior 

 end, and has a much less massive and prominent tuberosity. 



Materials are yet lacking to determine how wide is the range of variation in the 

 skeleton of the different species of Elotherium. So far as I have been able to observe, 

 there are no important differences between the species, save those of size and proportions, 

 the larger forms having more massive as well as longer bones. In particular, the great 

 John Day species have exceedingly heavy limb and foot bones. 



XI. The Relationships of Elotherium. 



There has been a very general agreement, among those who have made a study of 

 this genus, regarding the systematic position of Elotherium. The acute, compressed pre- 

 molars have, however, led some observers to see affinities with the Carnivora and de Blain- 

 ville went so far as to include the genus in his carnivorous family Subursi. Almost 

 every other writer has referred these animals to the suillines. Leidy says of it : " Elothe- 

 rium is a remarkable extinct genus of suilline pachyderms Its allies among 



extinct genera are Chozropotamus, Palceochcerus, Anthracotherium, and among recent 

 animals the Hog, Peccary and Hippopotamus " ('(39, p. 174). Kowalevsky expresses the 

 same idea in a more definite and specific way : " Schon bei dem ersten Anblick cler 

 Bezahnung bleibt kein Zweifel fiber die Familie zu der diese Form gehiirt, namlich den 

 Suiden ; sie bildet aber darin wegen des auffallenden Banes der didactylen Extremita'ten 

 eine sehr eigenthumliche Gattung. Plotzlich konnte eine derartige Form sich nicht 

 bilden, das Entelodon hatte gewiss Vorahnen, deren Knochenbau einen allmaligen 

 Uebergang von der tetradactylen zu der didactylen Form vermittelten, bis heute aber 

 sind uns solche noch ganzlich unbekannt " ('76, p. 450). Zittel refers the genus to the 

 Achcenodontince, a subfamily of the Suidm ('94, p. 335). Marsh erects a separate family 

 for the genus, and says of it : " The Elotheridce were evidently true suillines, but formed 

 a collateral branch that became extinct in the Miocene. They doubtless branched off in 

 early Eocene time from the main line which still survives in the existing swine of the old 

 and new worlds" ('94, p. 408). Schlosser has expressed a somewhat different opinion 



