M. Talbot — Podokesaurus holyokensis. 477 



helps to confirm his observation. In Anchisaurus, the femur 

 is much bent and the fourth trochanter is high up toward the 

 proximal end ; and all the limb bones are much stronger. The 

 pubis of Anchisaurus is shorter, and runs at almost a right 

 angle to the vertebral column ; nor is it expanded at its distal 

 end, as it is in this form. On the other hand, there is a general 

 similarity in the size of the corresponding vertebrae, though 

 those of the caudal region of Anchisaurus are not quite so 

 long and slender. 



Compsognathus longipes Wagner (fig. 6), from the Jurassic 

 of Bavaria, corresponds quite closely with this form in length 

 and general proportions of the limbs, in the shape of some of 

 the neural spines, especially those just anterior to the scapu- 

 lar region, and in the general shape of the ischium. The pubis 

 of Compsognathus is much shorter, proportionally, however, 

 makes a larger angle with the vertebral column, and is much 

 more expanded at its distal end. The shaft of the ischium 

 is not so slender nor so uniform in width. 



Classification. 



jSTo attempt at a definite placing of this fossil will be made 

 in this paper, but certain conclusions reached by the foregoing 

 study will be stated. The fossil is interpreted as that of a 

 carnivorous dinosaur because of the length, shape, and position 

 of the pubis and the absence of a postpubis. Since no jaw 

 has been found and there is no proof of the presence or absence 

 of an ascending process from the astragalus, the determination 

 of its position among the dinosaurs depends on the character 

 of the pubis and the presence or absence of a postpubis. The 

 position and length of the pubis are more nearly like those of 

 the carnivores than those of the herbivores, and there seems to 

 be no postpubis. The ischium is shaped somewhat like the 

 bone in Scelidosaurics harrisoni Owen, that von Huene 

 describes as the ischium, with a query, however, stating that it 

 may be the pubis, but not accepting that interpretation because 

 he can find no obturator foramen.* 



The short, slender humerus and the long, straight hind- 

 limb bones, together with the well-developed fourth trochanter, 

 are indicative of bipedalism. The length of the tibia, much 

 greater than that of the femur, the extreme length of the meta- 

 tarsals, over half that of the tibia, and the very light construc- 

 tion of the skeleton, indicate rapid locomotion, which Lull 

 uses as an indication of adaptation to climatic conditions, argu- 

 ing that this animal must have been able to travel fast and 



* Ueber die Dinosaurier der Aussereuropaeiscken Trias, F. von Huene, p. 57. 



