THE OSTEOLOGY OF ELOTHERIUM. 321 
withers. These spines are figured as having curious expansions at the tips, which are 
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 detcrmine 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 haying more massive as well as longer bones. In particular, the great 
John Day species have exceedingly heavy limb and foot bones. 
XI. Tue Retationsures oF ELorHEerium. 
There has been a very general agreement, among those who have made a study of 
this genus, regarding the systematic position of Hlotheriwm. 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 carniyorous family Subursi. Almost 
every other writer has referred these animals to the suillines. Leidy says of it: ‘‘ Hlothe- 
rium is a remarkable extinet genus of suilline pachyderms. .... Its allies among 
extinct genera are Cheropotamus, Palwocherus, Anthracotherium, and among recent 
animals the Hog, Peccary and Hippopotamus” (769, p. 174). Kowalevsky expresses the 
same idea in a more definite and specific way: “Schon bei dem ersten Anblick der 
Bezahnung bleibt kein Zweifel tiber die Familie zu der diese Form gehdrt, niimlich den 
Suiden ; sie bildet aber darin wegen des auffallenden Baues der didactylen Extremitiiten 
eine sehr eigenthtimliche Gattung. Pl6tzlich konnte eine derartige Form sich nicht 
bilden, das Entelodon hatte gewiss Vorahnen, deren Knochenbau einen allmiiligen 
Uebergang von der tetradactylen zu der didactylen Form vermittelten, bis heute aber 
sind uns solche noch ginzlich unbekannt” (76, p. 450). Zittel refers the genus to the 
Achenodontine, a subfamily of the Suid (94, p. 335). Marsh erects a separate family 
for the genus, and says of it: “‘The Hlotheride 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 
