368 THE ANATOMY OF VEETEBEATED ANIMALS. 



In the ninth dorsal vertebra the postzygapophysis pre- 

 sents an articular surface on its dorsal side, and the pre- 

 zygapophysis of the tenth vertebra bends round so as to 

 overlap this surface. This character is continued in the 

 succeeding vertebrae as far as the first sacral. The trans- 

 verse processes of the penultimate and last lumbar vertebi-se 

 are tolerably long, but they are inclined forwards as well as 

 outwards, and do not articulate with one another, or with 

 the first sacral. 



In the skull the supraoccipital is inclined upwards and 

 forwards into a great transverse crest, to which the parietals 

 contribute but Little. The parietals are early ankylosed. 

 The temporal ridges remain widely separated in the middle 

 of the roof of the skull. 



The frontal bone has a post-orbital process, and so has 

 the jugal, but the two do not meet so as to bound the orbit. 

 The lachrymal is very large, and its two canals open on the 

 face. The nasals are very long, and the premaxillse unite 

 with them for a great distance. There is a praenasal bone, 

 or ossification of the cartilaginous septum of the nose. The 

 bony palate extends back beyond the level of the last molar. 

 The base of the external pterygoid process is not perforated. 

 The surface for the articulation of the lower jaw is trans- 

 versely elongated, convex from before backwards, and 

 bounded behind and internally, by a post-glenoidal ridge. 



The tympanic bulla is very large, and the exceedingly 

 long bony meatus curves upwards and outwards, between 

 the squamosal and the mastoid, with both of which it is 

 ankylosed, to the root of the zygoma, where its aperture 

 looks almost directly upwards. The post-tympanic is 

 closely appressed to the post-glenoidal process, so as, with 

 the latter, to encircle the meatus. The proper mastoid is 

 distinct, though short, but there is a very long paramastoid 

 developed from the exoccipital and extending behind and 

 below the mastoid. 



The rami of the mandible are completely ankylosed at 

 the symphysis. There is a long perpendicular portion of 

 the ramus. The condyle is transversely elongated and 



