THE SKULL IN THE CHAMELEONS. 93 



The junction of the postorbital with the frontal and parietal is by a broad foot-shaped 

 expansion (fig. 3), with a sinuous edge growing into the frontal and grown into by it. 



The squamosal (sq) forms the hinder and lower boundary of the temporal enclosure ; 

 its hinder snag runs up and binds on the outer snag of the parietal ; its jugal process 

 runs forwards inside the lower process of the postorbital ; its body runs downwards 

 and forwards, and rests upon the otic process of the quadrate, where there is a proper 

 (flat) joint with a cartilaginous facet. This bone stands over the front and outside of the 

 quadrate head; but inside and somewhat behind there is another and smaller bone 

 (figs. 1, 4, and 6, s.t): this is the very constant Lacertilian supratemporal, which is 

 jammed in between the opisthotic (parotic) region and the squamosal. The junction 

 of the postorbital and squamosal, below the lower temporal space, is lost in the adult 

 (Plate XVI. fig. 1), these bones meeting higher up; thus the enclosed space is then 

 between these bones (with the small parietal added) on the outside and the great inter- 

 parietal crest on the inside. In front, over the olfactory sacs, we have the two small 

 nasals (fig. 3, «). separated from each other by the top of the nasal process of the 

 premaxillary [n.px). 



Outside and behind these are the large ear-shaped prefrontals (p-f), which are both 

 anteorbital and supraorbital in position; their pointed hind part binds against the 

 narrow end of the frontals, whilst their broad fore end protects the nasal wall. 



The infero-lateral bones have their fore part finished into an arch by the club-shaped 

 body of the premaxillary (pa.-) : this (fig. 3) is free above ; but the maxillaries nearly meet 

 below it (fig. 2). The latter bones (mx) rise high behind the alinasal ring to meet the 

 prefrontal, and then drop suddenly beneath the small unguiform lacrymal (I) and the 

 styloid fore part of the jugal (J); the latter bone is falciform, and finishes the orbit 

 below and behind, running up to bind over the long arcuate descending process of the 

 postorbital. 



The submucous bones of the palate (fig. 2) are in three pairs, with an odd one in 

 front: this is the vomer («), a lanceolate ossicle, hollow above and below, and broader 

 in the latter region than above ; it is wedged in between the fore end of the palatine 

 plates of the maxillaries in front, and behind the ascending submesial spur of the 

 palatines behind. These bones (pa) have a falcate outer region below, with the con- 

 vexity inside ; here each bone rises and is arched, meets its fellow, and sends forwards 

 a sharp ethmo-palatine spur, as in Birds. 



The pterygoid and transpalatines {pg,t.pa) have much of their adult shape — the 

 former ending by a point under the palatine, but only reaching to one third of that bone, 

 two thirds of its length from the vomer, and not touching it, as in most " Carinate " 

 birds and Hatteria. The investing bones of the mandible (fig. 6) are quite similar 

 to those of the adult; this part only increases in size after hatching; the relative 

 proportion of its elements remains much the same throughout life. 



VOL. XI.— PART III. No. 6. — March, 1881. q 



