41 



depression in the median plane between the points of attachment of 

 the nerve. This depression is the first indication of the median furrow, 



n, nov 



Fig. 5. Section in the horizontal plane of the brain of a Squalus embryo 

 41,5 mm long. From the MiNOT collection, No. 369, sec. 57. The lower figure shows a 

 portion of the upper section more highly magnified. A, X oc. 2, obj. -/g ; B, X oc. 2, 



