No. 2.] SCAPULAR AND PELVIC ARCHES. 239 



ligament with a third anterior to them. These are the last 

 ribs, and they are followed by a pair of sacral vertebrae whose 

 diapophyses are united distally. 



Remarks. This pelvic element is probably the iliopectineal 

 element of Furbringer. The pelvis differs from that of Anely- 

 tropsis {antea) in the absence of iliac element. 



Comparison of the Leptoglossa. In Chalcides we have 

 nearly normal scapular and pelvic arches, while the limbs are 

 very much reduced, though not to be termed rudimental. In 

 the next stage of reduction, where all the limbs are present, but 

 rudimental, the two arches show a considerable degradation, 

 which is more marked in the scapular than in the pelvic. The 

 pelvic elements remain much as in Chalcides, but reduced in 

 size merely. In the scapular arch, the sternum loses two 

 costals, and the interclavicle loses the transverse processes. 

 The clavicles become simple, and the ossification of the scapula 

 and coracoid is reduced in extent. In Propus, where the fore 

 limbs are much as in Evesia, while the hind limbs have disap- 

 peared, the scapular arch has many points in common with 

 Evesia. Thus, the clavicle and interclavicle are simple, and the 

 sternum has only two costals. The scapular and clavicle are 

 much better ossified. On the other hand, the pelvic arch dis- 

 plays a great reduction. In Anelytropsis, appropriately to the 

 absence of fore limbs, there is no scapular arch. The pelvic 

 arch is greatly reduced ; but, curiously, there appears an element 

 which resembles a corresponding element in the snakes. This 

 arrangement is quite different from anything observed in the 

 other Leptoglossa or in the Diploglossa, but is not without 

 parallel in other Lacertilia, to be described later on. 



The reduction of the scapular elements proceeds in the Lep- 

 toglossa on much the same lines as observed in the Diploglossa. 

 The early simplification of the distal end of the clavicle is pecul- 

 iar to the Leptoglossa, as it is always simple in the Diploglossa. 

 The late stages of reduction of the sternum seen in the limbless 

 Diploglossa are not exhibited by any of the forms here described, 

 although they probably exist, since we have the Anelytropsis, 

 where the scapular arch is wanting. On the other hand, the 

 extreme reduction of the pelvis seen in Propus, where the ilium 

 only remains, has not been yet observed in the Diploglossa 

 without posterior limbs (Figs. 4, 5, 6). 



