Ancestral Elasmobranch. 



(TABLE III) 



PALXEO- 

 ZOIC. 



MESO- 



ZOIC. 



CXENO- 

 zoic. 



a 



-C 



CO 



_c 

 JH 



cc. 



Q. Q. cc C 



2 



8 

 E 



Ic 

 O 



Q- 



b 



Fig. 103. Scheme suggesting the interrelationships of Sharks, Chimseroids, 

 and Lung-fishes. 



98 



