PLATE 40. 



CARCHARIDAE. 



Fig. 1-3. ScAPANORHYNCHUS owsTONi. M. C. Z. 1048 (Page 28). 



1. Brain from above. 



2. Brain from the side. 



3. Brain from below. 



Compari.son of the brain of this species with that of Carcharias taiirus, Plate 41, proves that Scapano- 

 rhynchus is the more primitive of the two genera and conversely that Carcharias is much the more ad- 

 vanced. 



