560 - Heredity and Evolution 



CROCODILES 

 LIZARDS 

 SNAKES 

 TURTLES 



CROSSOPTERYGII 

 TELEOSTS -^ 

 GANOIDS 



CYCLOSTOMES 



UROCHORDA 



UNGULATA 

 SIRENIA 



CHIROPTERA 



INSECTIVORA 

 EDENTATA 



CEPHALOCHORDA 



Fig. 29-6. Probable interrelations of the chordates. (These groups are described in Chap. 32.) 



