GENERAL BIOLOGY 



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Fig. 20. The Axial Skeleton of the Frog. 



A. The skull and vertebral column of frog viewed from dorsal surface. 



B. The same -from the ventral surface. 



C. Lateral view of the urostyle ; a bristle is passed through the foramen for 

 the tenth spinal nerve. 



D. The branchial skeleton of the frog : O., orbital fossa ; pmx., premaxilla ; 

 mx., maxilla ; .q-j., quadrato-jugal ; na., nasal ; pf., parieto-frontal ; ex., exoccipital ; 

 fm., foramen magnum ; pro., pro-otic ; sq., squamosal ; sp.et., sphenethmoid ; 

 par., parasphenoid ; pal., palatine ; vo., vomer ; ptg., pterygoid ; av., atlas ; c., 

 centrum ; ar., neural arch ; zyg., zygapophysis ; trv., transverse process ; ur., uro- 

 style ; H., body of hyoid ; Ha., anterior cornu ; H .p., posterior cornu of hyoid. 



E. The skull of a frog, seen from the right side : a.c., Anterior cornu of hyoid ; 

 a.sp., angulo-splenial ; 6., body of hyoid ; col., columella ; d., dentary ; e.n., external 

 nasal opening ; f.p., fronto-parietal ; m., maxilla ; mm., mentomeckelian ; n., nasal ; 

 o.c., occipital condyle ; p.c., posterior cornu of hyoid ; p.m., premaxilla ; pro., 

 prootic ; pt., pterygoid ; q., quadrate ; q.j., quadratojugal ; sp., sphenethmoid ; sq., 

 squamosal. 



F. The skull of a frog seen from behind : col., Columella ; ex., exoccipital ; 

 /.m., foramen magnum ; o.c., occipital condyle ; pro., prootic ; pt., pterygoid ; q., 

 quadrate ; q.j., quadratojugal ; sq., squamosal ; IX.X., foramen for ninth and tenth 

 cranial nerves. 



G. The cartilaginous skull of a frog, seen from above after the removal of 

 most of the bones : a./., Anterior fontanelle ; au., auditory capsule ; cr., cranium ; 

 ex., exoccipital ; l.p.f., left posterior fontanelle ; nas., nasal capsule ; o.c., occipital 

 condyle ; pro., prootic ; pt., pterygoid ; q., quadrate ; q.j., quadratojugal ; sp., 

 sphenethmoid ; u.j., upper jaw bar. 



