214 OUTLINES OF CHORDATE DEVELOPMENT 



IV 



art 



eo 



FIG. 82. A. Anterior portion of chondrocranium of R. fusca during meta- 

 morphosis. Lateral view. After Gaupp, from Ziegler. B. Skull of 2 cm. 

 R. fusca, after metamorphosis. Dorsal view. Membrane bones removed from 

 left side. After Gaupp, from Ziegler. a, Auditory capsule; am, anterior maxil- 

 lary process; an, annulus tympanicus; art, articular process of palato-quadrate 

 cartilage; eo, exoccipital bone; /, fronto-parietal bone; fpo, prootic foramen; mx, 

 maxillary bone; n, nasal bone; o, olfactory cartilages; on, orbito-nasal foramen; 

 pa, anterior ascending process of palato-quadrate; pg, pterygoid bone; pi, 

 plectrum; pm, posterior maxillary process; pp, posterior ascending process of 

 palato-quadrate; pq, palato-quadrate cartilage; pt, pterygoid process of palato- 

 quadrate; px, premaxillary bone; qj, quadrato-jugal bone; II, foramen for optic 

 nerve; 777, foramen for III cranial nerve; IV, foramen for IV cranial nerve. 



