14 BAUR. [Vol. VII. 



The Postfrottto-orbital (Fig. 5). 



In the specimen before me the postfrontal is suturally united 

 with the postorbital ; this suture, however, is obhterated at the 

 ventral side of the bones. The larger portion of the postfrontal 

 articulates with the frontal ; the smaller posterior portion with 

 the parietal ; behind it is united to the postorbital only. The 

 postorbital is an L-shaped bone ; the long posterior branch joins 

 the quadrat ojugal in its whole length ; the short lateral branch 

 is connected with the jugal ; both articular faces come together 

 below. The quadrat ojugal joins, therefore, the jugal at this 

 point. In Varanus these two elements are co-ossified, but have 

 the same general position, but the bulk of the sutural part is 

 formed by the parietal ; this is probably produced by the reduc- 

 tion of the posterior part of the jugal; in Varanus the quad- 

 ratojugal is very much smaller, never reaching the jugal, which 

 is incomplete behind. 



TJie Squamosal (Figs. 20, 21). 



This is a relatively small element. It is that bone which has 

 been called opisthotic by Professor Cope ; but, of course, it has 

 nothing to do with this element, which is co-ossified with the 

 exoccipital ; it is the mastoid of Cuvier, the supratemporal of 

 Parker ; the homologue to the squamosal of the Crocodilia, Tes- 

 tudinata, Rhynchocephalia. We can distinguish three portions : 

 first, an upper one, which joins the parietal processes; second, 

 an inner one, which is suturally united to the paroccipital and 

 petrosal, and a lower one, which supports the quadrate. It is 

 connected besides with the quadrat ojugal, which covers loosely 

 its middle and outer portion. Both the squamosal and quad- 

 ratojugal support the quadrate. The suture, which unites it 

 with the paroccipital and petrosal, is very strong, and therefore 

 this element generally remains in connection with these bones. 



The Quadratojugal (squamosal) (Fig. 3). 



This element is of an ancre-like form ; the long anterior 

 process receives the postorbital in a very deep sutural groove ; 

 in front, it touches the jugal. The broad posterior portion covers 

 the squamosal. It contains an articular groove, which extends 



