336 O. C. Marsh—The Order Theropoda. 
The extremely narrow pelvis is one of the most marked 
features in this entire group, being in striking contrast to the 
width in this region in the herbivorous forms’ found with 
them. If the Zheropoda were viviparous, which some known 
facts seem to indicate, one difficulty, naturally suggested in the 
case of a reptile, is removed. 
Another interesting point is, the use of the large foot at the 
lower end of the pubes, which is the most massive part of the 
skeleton. The only probable use is, that it served to support 
the body in sitting down. That some Triassic Dinosaurs sat 
down on their ischia is proved conclusively by the impressions 
in the Connecticut River sandstone. In such cases 
was bent so as to bring the heel to the ground. The same 
action in the present group would bring the foot of the pubes 
to the ground, nearly or quite under the center of gravity of 
the animal. The legs and ischia would then naturally aid in 
keeping the body balanced. Possibly this position was assume 
habitually by these ferocious biped reptiles, in lying in walt_ 
or prey: 
Tue Hinp Lips. 
In the foot of Allosaurus fragilis, represented: in Plate XH, 
no tarsal bones of the second row were found, although the 
adjoining bones were nearly in their natural position. ether — 
the former were imperfectly ossified, or lost, in this instance — 
cannot be determined with certainty, but there is evidence — 
of the presence of these bones in several other members of the 
group. In the present foot, there were three functional digits — 
The metatarsals are very long, and fitted closely to each othet 
especially at their upper ends. The phalanges and claws were — 
mostly found near the positions here assigned to them. 
* Compsognathus is cited as an instance of this union, but in a careful study . 
the original specimen in Munich, the writer found evidence that the astraga ig 
distinct, although closely attached to the tibia. i roved a. 
conclusively (Morpholog. Jahrbuch, VIII). In the Stegosauride alone, among 
Dinosaurs, is the astragalus codssified with the tibia. This, however, 
not a character of much importance. : 
