44 
Northcutt 
Fiirure 16 Photomicrograph of a transverse section through the optic tectum of Lacerta stcula. 
Abbreviations S same as Figure IB. Note increased thickness of cellular laminae 
in neriventricular zone clear separation of laminae 6 and 7 of the central zone and poor y 
developed lamina 14. These tectal features characterize most living lizards and are very simi ar 
to the tectal pattern seen in Sphenodon (fig. 17). 
