OF THE SCAPULA IN THE BATRACHIA. 



PlPLD.E. 



199 



As in Palceobratrachics, the genera of this family have the 

 scapula entire, without the cleft which separates the pars 

 acromialis from the pars glenoidalis, at least partially, in all other 

 families. This, together with the marked reduction of the 

 scapula, constitute diagnostic characters for the Pipidge. 



Xenopus Wagl. 



X Icevis Daud. — Scapula vestigial ; subtriangular. Shaft and 

 pars acromialis completely absent ; pars glenoidalis containing 

 the circular depression of the glenoid cavity. Head of prsecora- 

 coid in contact with supra-scapula. Occasionally the scapula is 



Text-figure 3. 



Pectoral girdle of JCenopus la-vis. X2. 



(a) scapula distinct ; from without. 



(b) scapula not distinct ; from within. 



apparently wanting, having fused with the head of the prcecora- 

 coid ; in most specimens this fusion is more or less marked 

 making the boundaries of the vestigial scapula difficult to trace. 



Example. 



Length of prsecoracoid 10 units. 



,, scapula (at base) 2*4 



Breadth of ,, (expanded end) 2'1 



Length of supra-scapula 10*3 



X muelleri Ptrs. — Scapula as in X laivis. A figure of the 

 pectoral girdle is given by Peters *, in which it is absent. In 



* Peters, ' Reise nach Mossambique ' (1882) Taf. xxvi. 12 a. 



