PLATE 5 



EXPLANATION OF FIGURES 



25 Lateral view of the region around the foramen interventriculare in an 

 embryo of Chrysemys marginata having a carapace 10.6 mm. in length. Embryo 

 4 b. X 66|. Lateral hemisphere wall and lateral telencephalic plexus removed, 

 exposing the fissura chorioidea. 



26 Dorsal view of the forebrain of a 5.1 mm. embryo of Chrysemys marginata. 

 Embryo 1 a. X 80. 



27 Pen sketch of model of entire forebrain of embryo 4 b, showing the area 

 from which figure 25 was taken. X 25. 



538 



