CORTEX AND CORPUS STRIATUM 107 



caudate nucleus of mammals includes both this structure and the 

 older olfacto-striatum (his "bed nucleus of the stria terminalis"). 

 I have, accordingly, retained Elliot Smith's very appropriate 

 name, "hypopallium,'* for the anterior end of the dorsal ventricu- 

 lar ridge, and for the posterior end of this ridge I adopt Johnston's 

 term (1923, p. 461), "amygdaloid ridge." 



qenerci\ cortex 



pcjriform cortex 



hippocampal 

 cortex 



omi^qdalold r?dge 

 primitive amygdala 

 amij<jdoloid fissure 



Fig. 24. — Cross-section through the posterior part of the cerebral 

 hemisphere of the box-tortoise. 



Johnston (1916^) describes the development of the dorsal 

 ventricular ridge in turtles and states that the hypopallium of 

 my usage here is derived by ingrowth from the lateral margin 

 of the general cortex and that the amygdaloid ridge is similarly 

 infolded from the pyriform cortex. Hines (1923) has given an 

 account of the development of the corpus striatum complex in 

 the generalized reptile, Sphenodon, which differs in some respects 

 from Johnston's description of the turtle. The hypopallium is not 

 infolded from the lateral margin of the general cortex but is 

 developed in situ in a neostriatal ridge. The amygdaloid ridge 



