432 



J. B. JOHNSTON 



sen 



Fig. 10 A figure for the comparison of the selachian brain with that of the 

 turtle. The right half of the figure represents a section of the brain of Acanthias 

 (from '11 a, fig. 75). The left half represents a section at a corresponding level 

 of the brain of the turtle. Both drawings were made under the Edinger appa- 

 ratus and the grouping of cells is accurately represented. At this level in the 

 brain of Acanthias the nucleus parolfactorius lateralis appears to be confined to 

 the medial wall, but farther rostrad it has a broad connection with the deep 

 gray of the lateral wall quite as in mammals. It does not appear that this nu- 

 cleus represents an invasion of the medial walls by the striatum. It is rather a 

 primary component of the medial wall. 



