SKULL OF RANA TIGRINA. 



Text-figure 1. 

 prrt 



q po ^o 



Rana tigrina ; dorsal view of skull. 



a.l., aliiiasal process ; c.a., columella auris ; eo., exoccipital ; f., anterior foutaiiellc ; 

 f.o., fenestra ovalis ; fp , fronto-parietal ; m., maxilla ; »., nasal ; _p., palatine ; 

 p.c, palatal cavtilagre ; p^n., premaxilla ; p.nl., prenasal process ; po., prootic ; 

 ^.r.. rostral process; p.rA., rliinal process ; ps., pavasphenoid ; ^^., pterj'goid ; 

 q., quadrate cartilage ; qj., quadrato-jugal ; s., squamosal ; se., splienethmoid ; 

 sm., septo-maxillary ; s.n., septum nasi ; sp., septum dividing the anterior part 

 of the sphenethmoid ; st., stapes ; v., vomer. J, II, III, IV, V, VII, IX, X, 

 refer to the foramina for the exit of the cranial nerves. 



Text-fisnre 2. 



JX,X 



H. tigrina ; ventral view of skull. 

 For explanation of the letters see text-rig. i. 



1* 



