486 O. C. Marsh—On Dinosaurian Reptiles. 
If we compare some of the characteristic parts of the 
skeletons of these groups; e.g., of the true Crocodilia as 
existing to-day, the elodontia, the Aétosauria, and the 
Hallopoda, and all with the corresponding portions of the 
more typical Dinosaurs, the result may indicate in some 
measure the relationship between them. Taking first the 
FigurE 4.—Diagram of left fore limb of Hallopus victor, Marsh; seen from the 
left. 
FIGURE 5.—Diagram of left hind limb of same individual. Both figures are one- 
half natural size. 
Figure 6.—Left hind leg of Laosaurus consors, Marsh; outside view. One- 
sixth natural size. a, astragalus; c, caleaneum; f, femur; /”, fibula; 7, 
ilium; ds, iscnium; yg, pubis; p’, postpubis; ¢, tibia; f IV, V, first, 
fourth, and fifth digits. 
