490 Frofessof E. Burchhardt — On Hyperodapedon Gordoni. 



The general impression which these figures convey is that, even 

 on a more complete development of the skull than has already been 

 executed, the dorsal side, at any rate, would not present very 

 massive proportions. Yet, the surfaces of the bones themselves 

 are of a very hard and dense structure, and are possessed of ridges 

 and protuberances which leave no doubt as to their homogeneity 

 with the respective bones, even where their sutures are more 

 indistinct. These anatomical characters are especially well defined 

 on the maxillary and the jugular. 



The sutures form slightly serpentine lines, except between the 

 parietal and the prasfrontal, where they are serrated. The pr^- 

 maxillaries, which enclose the nasal cavity, as mentioned elsewhere, 

 terminate caudally in blunted points, which are broken off, but the 

 original form of which is preserved still as an imprint on the prgefrontal. 

 The margin of the nasal impinges somewhat on the median contours 

 of the pr^emaxillaries, apparently to lend them additional strength, 

 and to prevent their breaking out easily. Laterally they are held in 

 position similarly, by a coarsely indented margin of the maxillary. 



The limits of the lachrymals are more difficult of determination ; 

 firstly, because their ventral sides are embedded in the stone, 

 and secondly, because their dorsal surfaces are damaged. Their 

 existence, however, cannot well be doubted, if we may judge from 

 analogy in Bhyncliosaurus, where they are most clearly defined. 



I fully concur with Dr. Smith Woodward in his determination of 

 the middle of the cranium, although the lateral margin of th& 

 prfefrontal appears to me to be clearly enough circumscribed. 



Features actually new as to their interpretation appear again only 

 behind the orbit, where the postorbital is conspicuous both by its 

 shape, its position, and by being entirely excluded from participation 

 in the orbital foramen. It forms the whole of the anterior portion, 

 and part of the lateral contour of the temporal fossa. Its posterior 

 end is unfortunately broken off, but no doubt can be entertained 

 as regards its original shape, from the evidence supplied by th© 

 surface of its underlying squamosal, on which the outlines of its 

 margin can be identified distinctly. 



The squamosal itself is in a very imperfect state of preservation. 

 It is connected with the pr^orbital, and participates in the formation 

 of the supratemporal foramen ; a ramus of the quadrato-jugular 

 ascends to the latter, on the outer side of the squamosal. The 

 squamosal is represented in its greater part only by the mould which 

 it has left in the stone. It is quite probable that a posterior temporal 

 fossa was formed by the squamosal and a branch of the quadrate 

 bone, but on this point the information to be obtained from literature 

 is of too vague a nature to allow our arriving at any definite 

 conclusions thereon. 



The quadrate itself is a broad ish, disk-like bone, deepened in 

 the centre. Its complete immobility can be ascertained from the 

 fact that it is joined to the squamosal and the quadrato-jugular 

 by suture. It could not have participated in the formation of the 

 lateral temporal foramen ; that office was reserved to the quadrate- 



