ORDER DINOSAURIA. 



1177 



and maxillae, after the fashion obtaining in Pterodactyles and Birds. 

 And it is probable that a similar arrangement exists in the other 

 members of the suborder. It will be observed from the figure 

 that the jugal bifurcates posteriorly to form the anterior and inferior 

 borders of the orbit ; while the quadratojugal joins the maxilla 

 without the intervention of the jugal, which is thrust up. These 

 peculiar features are repeated, as will be noticed below, in one 

 genus of the Ornithosauria. The pelvis is of the general type of 



Fig. 1076. — Left lateral aspect of the skull of Diplodocus longus ; from the Upper Jurassic 01 

 North America. One-sixth natural size. The position of the nares at the top of the skull is 

 incorrect. (After Marsh.) 



that of the last family ; but the distal extremity of the ischium is 

 not expanded. 



Family CETiosAURiDiE. — This family is typically represented by 

 the English genus Cetiosaurus, which, so far as can be determined 

 from the characters of the scapula and pelvis, appears to be so 

 nearly related to the American Morosaurus that there seems every 

 reason for including the latter in the same family. Cetiosaurus 

 occurs typically in the Lower Jurassic Great Oolite, and Forest- 

 Marble of Oxfordshire and Northamptonshire, where we meet with 

 the huge C. oxoniensis. Comparatively small teeth from the same 

 deposits, described under the earlier name of Cardiodon rugulosus, 

 are of the same general type as those of Hoplosaums, but have rela- 

 tively smaller crowns, with a more incurved summit, and are clearly 

 distinct from the last-named genus. Professor Phillips referred 

 teeth of this type to C. oxoniensis, but from their small size they 



