40 THE ORIGIN OF VERTEBRATES 
MAMMALIA. 
REPTILIA. 
AMPHIBIA., 
TELEOSTEA. 
AMMOCCETES. 
Fig. 19.- CoMPaRIsON OF VERTEBRATE BRAINS. 
CB., cerebellum ; PT., pituitary body; PN., pineal body; C. STR., corpus striatum ; 
G.H.B., right ganglion habenule. J., olfactory; IZ., optic nerves, 
