624 



REPTILIA. 



which are furnished with small pointed teeth. In the posterior region 

 of the skull we have still to notice the large ex-occipitals with which the 

 opisthotics are fused, and which are continued into the conspicuous 

 parotic processes. The lateral walls of the brain-case are largely formed 

 by the paired pro-otics. Internally, an important bone, the epipterygoid 

 or "columella" (not to be confounded with the columella or stapes of 

 the ear), extends from the pro-otic to the pterygoid. The orbit is 



pt.o p.e 



pro \ps ' 



Pf 



sti 



FIG. 341. Side view of skull of Lacerta. After W. K. Parker. 



px.) Premaxilla ; mx., maxilla; /., lachrymal; /., jugal ; t.pa., 

 transpalatine ; epg., epipterygoid;/^-., pterygoid; bpg., basi- 

 pterygoid ; b. 0., basioccipital ; q.^ quadrate; 0c.c., occipital 

 condyle ; sg. t squamosal;/r.<?., pro-otic ; /i?.0.,postorbital ; j/.i, 

 **.2, supratemporals ; ps., presphenoid (the optic nerve is seen 

 issuing in front of the end of the reference line); /.<?., mes- 

 ethmoid ; s.0&., supraorbitals ; pf.^ prefrontal ; ft., nasal ; ar. t 

 articular ; ag'., angular ; sag., surangular ; cr. t coronary ; </., 

 dentary. 



bounded posteriorly and inferiorly by the jugals. There is no ossified 

 quadrato-jugal, and thus the lateral temporal fossa is open below in the 

 dried skull (contrast Hatteria}. The other fossae of the dried skull are 

 the supra-temporal on the upper surface, and the posterior-temporal on 

 the posterior surface. 



Each half of the lower jaw is composed of six bones, which use in 

 the adult. The two rami are sutured to one another in front. 



