MESOZOIC LACERTIANS. 127 



and rounded, so as to project from the fang ; they converge at the fore and hind 

 parts of the tooth, and unite at an acute angle (fig. 2, c, r), to form the long, basal 

 points (fig. 3, i, s) of the serrated half of the crown. The foregoing characters 

 apply to the majority of the teeth of EcMnodon, 



A portion of the left maxillary bone, with its outer surface exposed, is repre- 

 sented in PL 11, fig. 1, and in outline, of the natural size, at «. The anterior, 

 probably premaxillary, part has been detached and broken. Three teeth, more 

 or less fractured, project from sockets in the alveolar border of this part; their 

 crowns are less expanded than in the typical maxillary and mandibular teeth. 

 Part of the boundary of an external nostril is indicated at «, the larger maxillary 

 fragment the first two teeth present a similar form, and the entire crown of the 

 second shows it to be longer, as well as more slender, than the posterior teeth ; 

 it resembles a canine tooth in both shape and position, the crown being subcom- 

 pressed and slightly recurved, as well as sharp-pointed. It would serve well 

 to pierce and retain a living prey. It recalls a dental character of Iguanodon. 



The tooth succeeding the laniariform one presents the typical characters ; 

 In fig. 1 are shown the impressions of four of the teeth preserved in the slab 

 (fig. 2). Above the first impression (o, fig. 1) is the crown of a successional tooth, 

 about to displace the tooth (o, in fig. 2). The outer side of maxillary teeth is 

 shown, magnified, at i,b. 



The remainder of the upper maxillary, with part of the palatine and pterygoid 

 bones of the left side, are represented, magnified, in fig. 2, and of the natural size, 

 in outline, at „. The extent of the inner alveolar wall, effecting, with the cross 

 partitions, the lodgment of the teeth in sockets, is here demonstrated. The 

 expanded crowns of the teeth come into contact. The inner surface of the crown 

 is shown at b, in which the middle longitudinal rising is rather less prominent than 

 on the opposite surface. The fore part of the crown is represented at e. The 

 outer side of a portion of the right maxillary, with eight contiguous molars, is 

 represented in fig. 3, and of the natural size, in outline, at a. There is a Unear 

 row of small foramina above the alveolar border. The median longitudinal rising 

 of the crown of the teeth is more strongly marked on this, the outer surface. In 

 fig. 4 is represented the inner surface of the posterior part of a right maxillary, 

 containing six contiguous teeth, with a less prominent or less defined median 

 rising of the teeth in this fragment ; the last three teeth gradually decrease in size. 



The inner surface of a portion of a mandibular ramus, with eight contiguous 

 teeth, is represented at fig. 5, and in outline, of the natural size, at a. The fore 

 part of a right ramus, consisting chiefly of the dentary element, is represented 

 in figs. 6 — 8, and of the natural size, in outline, at «. Fig. 6 gives the outer side, 

 but the whole vertical extent of the bone is only preserved at the symphysial end. 

 The apex of a young tooth projects from the fifth of the sockets here preserved ; 



