198 PELOBATID^. 



smooth, and tlie dermo-ossification, as it develops, 

 produces granular asperities which may become con- 

 fluent into alveolar ridges, producing a pitted appear- 

 ance. In very old specimens the sutures between the 

 nasals, the ethmoid, and the fronto-parietal may become 

 obliterated. 



Vomers rather large, variable in shape, extending 

 or not to the palatines, which are strongly ossified. 

 On the palatal side the ethmoid extends posteriorly to 

 about the middle of the length of the parasphenoid. 

 Latter large, J.-shaped, its anterior pointed extremity 

 produced to between the palatines. Pterygoids not 

 reaching the palatines, extensively in contact with 

 the parasphenoid. Stapes absent. 



Mento-Meckelian or symphysial bones distinct on 

 the inner side only. 



Hyoidalarge broad cartilaginous plate, with slender 

 postero-lateral processes ; anterior processes much 

 expanded and confluent with the lateral wings, en- 

 closing a small fenestra; ceratohyal cornua with 

 short posterior portion detached from the body of 

 the hyoid ; thyrohyals large, massive, in contact at 

 the base, diverging and more or less expanded poste- 

 riorly. 



Vertebral column once and a half to twice as long 

 as the skull. Spine closed above, the neural arch 

 produced posteriorly into a strong median process 

 between the zygapophyses. Three anterior diapo- 

 physes strong and long, especially the second, which 

 bears a more or less distinct dorsal knob or process 

 as on the corresponding rib of Discoglosfms, — the first 

 directed obliquely forwards, the second and third 

 nearly horizontal; the following short and slender, 

 directed forwards. Sacral vertebra with very strongly 

 dilated diapophyses, the transverse diameter of which 

 is twice and a half to nearly three times in the axial ; 

 urostyle short, not longer than the sacral wings, and 

 fused with the sacrum, to the diapophyses of which 

 its anterior portion contributes if these jDrocesses be 



