260 FREDERICK TILNEY 
24 
33 32 
Vig. 26 Mesial view of forebrain reconstruction of 20 mm. Mustelus. X 75. 
The unshaded area shows the cut surfaces of the reconstruction. 2, chiasmatic 
process; 3, cerebellum; 4, chiasm; 7, epiphysis; 18, infundibular evagination; 
24, mid-brain; 25, mammillary region; 32, post-chiasmatic eminence; 33, post- 
chiasmatic recess; 36, post-infundibular eminence; 41, supra-optic crest; 42, 
supra-optic recess; 44, telencephalon; 46, tubercle of the floor of Schulte; 47, 
velum transversum. 
and has expression upon the surface in a large protuberance 
caudal to the chiasm, the post-chiasmatic eminence. This 
eminence already shows a demarcation into a shallow post- 
chiasmatic groove in which the ventricular floor is thin and two 
large, thick-walled protuberances, the lateral processes of the 
post-chiasmatic eminence or inferior lobes. The cavity of the 
