0. C. Marsh—The Order Theropoda. 331 
The parietal bones are of moderate size, and there is no 
parietal foramen. The median suture between the parietals is 
Aiahadenias but that between these bones and the frontals is 
Inet. 
The frontal bones are of moderate length, and are closely 
united on the median. line, the suture being obliterated. Their 
union with the nasals is apparent on close inspection. 
The nasal bones are more elongate than the frontals, and the 
suture uniting the two moieties is obsolete. These bones sup- 
port entirely the large compressed, elevated horn-core, on the 
median line. The lateral surface of this elevation is very 
rugose, and furrowed with vascular grooves. It evidently sup- 
ported a high, trenchant horn, which mnst have formed a most 
powerful weapon for offense and defense. No similar weapon 
is known in any of the Dinosauria, but it is not yet certain 
whether this feature pertained to all the members of this 
family, or was only a generie character.* 
€ premaxillaries are separate, and each contained only 
three functional teeth. In the genera Compsognathus an 
egalosaurus, of this order, each premaxillary contained four 
teeth, the same number found in the Sauropoda. In the 
hus Creosaurus, from the American Jurassic, the premaxil- 
aries each contain five teeth, as shown in Plate IX, figure 3. 
The maxillary bones in the present specimen are large and 
Massive, as shown in Plate VIII, figure 1. They umite, in 
front, with the premaxillaries by an open suture; th 
hasals, laterally, by a close union; and, with the ugal behind, 
*Y Squamosal suture. The maxillaries are provided each with 
fifteen functional teeth, which are large, powerful, 
* The “horn” of Iguanodon described by Mantell, and since regarded as a 
carpal spine, proves to be the distal phalange of the thumb. 
