378 NOTES ON THE CANIDZ OF THE WHITE RIVER OLIGOCENE. 
none of the specimens is the series preserved entire. Probably, however, these vertebree 
numbered thirteen, as is commonly the case among the recent representatives of the 
family. The specimen of C. geismarianus: figured by Cope (’85, Pl. LX Xa) has the 
posterior ten thoracics in place, and there must have been at least three additional ones. 
The anterior vertebre of this region have very small, contracted centra, but long and 
prominent transverse processes and neural spines which are relatively higher and more 
slender than in Canis, and are also inclined more strongly backward than in the latter. 
Posteriorly the centra become longer, broader and more depressed, and are quite distinctly 
keeled in the median ventral line. In addition to this median keel are two shorter and less 
prominent lateral ridges, which, however, terminate behind in distinct tubercles and thus 
give avery characteristic appearance to these vertebrae. The transverse processes become 
more and more shortened and the neural spines lower, less strongly inclined, but more 
compressed and broadened at the base (antero-posteriorly). The antepenultimate thoracic 
(presumably the eleventh) is the anticlinal vertebra, of which the neural spine is low, 
broad, compressed and erect. The penultimate (? twelfth) and last (? thirteenth) thora- 
cies are very much like lumbars in appearance and structure, but have no transverse 
processes, while in Canis these processes, though small, are quite distinct on the twelfth 
and thirteenth thoracies. Large, heavy and prominent anapophyses and metapophyses 
are present on the last two thoracics. 
Of lumbar vertebre this genus probably possessed seven, that many being preserved 
in position and in connection both with the thoracies and with the sacrum in Cope’s speci- 
men of C. geismarianus. In the White River material at my command not more than 
five lumbars have been found in association with any one individual, but the series is 
obviously incomplete, and there is no reason to suppose that C. gregarius differed in this 
respect from the John Day species. The lumbar region is proportionately long and stout 
and the individual vertebrae are quite massively constructed (7. e. for so small an animal), 
indicating a powerful musculature in this region. The centra increase in length up to 
that of the penultimate vertebra, while the first and the last are the shortest of the 
series. These centra are broad and depressed, and bear distinct median ventral keels, 
while the lateral ridges and tubercles are present on the first two vertebrae, but not on 
the last three. The faces are kidney-shaped, slightly convex in front and concave 
behind, and are placed obliquely with reference to the long axis of the centra. This 
obliquity is to provide for the curvature of the loins, which rise to the pelvis, the rump 
standing considerably higher than the shoulders. The transverse processes, which are 
quite short on the anterior lumbars, increase steadily in length up to the sixth, where 
they become yery long; they are slender, depressed, pointed and curyed forward. The 
neural spines are low, compressed and thin, broad at the base, narrow and pointed at 
