214 DINOSAURS OF NORTH AMERICA. 



A comparison of this pelvis with that of Stegosaurus (PI. LXXXI) 

 shows some points of resemblance, but a wide difference in each of the 

 elements. Tbe pubis corresponds in its essential features to the pre- 

 pubis of Stegosaurus, but the postpubis is represented only by a short 

 process. 



THE TOSTERIOK LIMBS. 



The femur is short, with the great trochanter well developed. The 

 shaft is comparatively slender, and the distal end much expanded. 

 The third trochanter is wanting, or represented only by a rugosity 

 (PI. LXVIII, fig. 1). 



The tibia is of moderate length, and resembles that of Stegosaurus. 

 The shaft is slender, but the ends are much expanded. The fibula is 

 very slender, and the distal end was closely applied to the front of the 

 tibia (PI. LXVIII, fig. 2). In adult individuals the astragalus is firmly 

 coossified with the distal end of the tibia, as in Stegosaurus. 



The metatarsal bones which were functional are rather long, lint 

 massive. Their phalanges are stout, and the distal ones broad and 

 rugose, indicating that the digits were terminated by very strong hoofs 

 (PI. LXIX, figs. 7-12). 



All the limb bones and vertebra; in Triceratops and the nearly allied 

 genera are solid. 



THE DERMAL ARMOR. 



Besides the armature of the skull, the body also in Triceratops was 

 protected (PI. LXX). The nature and position of the defensive parts 

 in the different forms can not be determined with certainty, but vari- 

 ous spines, bosses, and plates have been lound that clearly pertain to 

 the dermal covering of Triceratops, or nearly allied genera. Several of 

 these ossifications were probably placed on the back, behind the crest 

 of the skull, and some of the smaller ones may have defended the throat. 

 as in Stegosaurus. 



TOKOSAURUS. 



In the type specimen on which this genus was based the greater 

 portion of the skull is preserved, and this presents so many points of 

 interest that a figure of it, one-twentieth natural size, is here given in 

 PI. LXII, fig. 1. The second species is represented also by the skull, 

 which, although not complete, supplements the type in several important 

 respects, and figures of its posterior portions are likewise given in the 

 same plate and in fig. 54, on the opposite page. Both specimens are of 

 gigantic size, one skull measuring 5J feet across the parietal crest, and 

 the other is nearly as large. They differ widely, moreover, from the 

 huge horned dinosaurs hitherto found in the same general horizon, and 

 in the skull present characters of much interest. 



THE SKULL. 



In Torosaurus lotus, the species first described, the skull appears 

 wedge-shaped when seen from above, as shown in PI. LXII. The facial 

 portion is very short and pointed, and somewhat suilline in form. The 



