464 Bulletin Amei-ican Museum of Natural History. [Vol. XIX. 



dinosaurs also serves to show its distinctness. The sacrum 

 differs from that of Aristosnclins in the possession of four 

 primary sacral ribs. The elongation of the second digit of 

 the manus resembles that in Archceopteryx, but was evidently 

 for a dififerent purpose. 



