MEGALOSATTRID^. 



157 



Family MEGALOSAURID^E. 



Teeth usually with serrations on some portions of the anterior 

 border ; mandible at least in some instances (Ceratosaurus, fig. 26) 

 with lateral vacuity. Vertebras with lateral pits and fusiform 

 central cavities ; cervicals shorter than dorsals, with free ribs ; 

 sacral arches generally supported by single vertebras. Humerus 

 with head imperfectly differentiated from tuberosities, and deltoid 

 crest terminating abruptly; four or five digits in manus; femur 

 slightly longer than tibia, with head much flattened and placed 

 obliquely to condyles ; astragalus short and wide ; three to five 

 digits in pes. 



This family is taken to include the Zanclodontidce, Labrosauridce, 

 and Ceratosauridce of Marsh. 



Fig. 26. 



Ceratosaurus nasicornis, Marsh. — Left lateral view of skull ; from the Upper 

 Jurassic of North America. \. a, nares ; b, bony prominence ; c, preorbi- 

 tal vacuity ; d, orbit ; e, infratemporal fossa ; f, mandibular vacuity ; t, 

 transverse bone. (From the ' Amer. Journ.') 



Genus ARISTOSUCHUS, Seeley l . 



Vertebras with a longitudinal fusiform cavity in the middle of 

 centrum ; sacrum with probably five vertebrae, each of which 

 supports its own arch. Pubes with very long bony union on the 



Quart. Journ. Geol. Soc. vol. xliii. p. 221 (1887). 



