LACEETILIA. 



339 



cipital, prootic and opisthotic) is prolonged outwards into 

 parotic processes (as in the Chelonia), to the outer end of which 

 the quadrate is articulated (usually moveably). There is a small 

 bone at the outer ends of these processes, called the supra- 

 temporal {14). There are no alisphenoids, orbitospheuoids, 

 or presphenoids ; tliis part of the skull wall beuig mahily mem- 

 branous with tracts of cartilage. There is in all, except the. 

 AmpJiishaenidae and Chamaeleonidae and the genus Anniella, a 

 rod-shaped bone — the epipterygoid — extending from the parietal 



Fio 185 —Sternum with ribs and shoulder girdle of A, Iguana ; B, Lophiurus ; C, Plaiydacty 

 lus St sternum ; ep interclavicle (episternum) ; Mst posterior prolongation of sternum 

 carrying sternal ribs ; Co coracoid ; CI clavicle ; Cr sternal crest ; X posterior dontinuation 

 of sternum without ribs (xiphistemum) (from Gegenbaur). 



to the pterygoid on each side, in close contact with the mem- 

 branous or cartilaginous wall of the skull (23). This bone is some- 

 times called the columella cranii which is a bad name because 

 it leads to confusion between it and the columella auris. Those 

 lizards which possess it have been called the Kionocrania. There 

 is a small ossification hi some Chelonia between the descending 

 process of the parietal and the pterygoid which seems to corre- 

 spond to it. The occipital condyle is mamly formed by the 

 basioccipital but the exoccipitals participate. It is double m 

 the AmpMshaenidae. The opistliotic is fused with the exoccipital 

 and the epiotic with the supraoccipital, the prootic remaining 

 separate. The parietals are not jouied suturally to the 



