SKELETON. 45 



a. Vertebrae opistliocoelous, imbricate and com- 

 pletely covering the spinal cord above ; 

 autogenous ossified ribs attached to the 

 anterior diapophyses ; sacral vertebra with 

 dilated diapophyses overlapping the ilia; 

 urostyle with transverse processes at the 

 base ; omosternum cartilaginous or absent ; 

 sternum cartilaginous, with two posteriorly 

 diverging limbs ; eight elements in the 

 carpus, two in contact with radius-ulna ; 

 four distal tarsal elements ; long bones with 

 cartilaginous epiphyses (DiscoGLOSSiDiE). 



1. Fronto-parietal fontanelle small, covered 



over in very old specimens ; palatines 

 present; zygomatic branch of squamosal 

 forming a suture with maxillary ; second 

 rib with posterior process ; dorsal vertebras 

 with a strong postero-median neural pro- 

 cess ; sacral vertebra with moderately 

 dilated diapophyses and two condyles for 

 urostyle Uiscoglossus. 



2. Fronto-parietal fontanelle very large; pala- 



tines absent ; second rib with posterior 

 process ; postero-median neural process of 

 vertebra absent or very short ; sacral ver- 

 tebra with very strongly dilated diapo- 

 physes and a single condyle for urostyle. 



Bombinator. 



Tibia shorter than femur B. igneus. 



Tibia as long as femur ... 7?. pachypus. 



3. Fronto-parietal fontanelle large ; pala- 



tines present ; a cartilaginous supra- 

 orbital ; second rib without process ; pos- 

 tero-median neural process of vertebra? 

 absent or very short ; sacral vertebra with 

 strongly dilated diapophyses and two 

 condyles for urostyle .... Alytes. 

 Fronto-parietal bones in contact only quite 

 posteriorly, embracing a very large sole- 



