PLATE XI 



SKULLS OF Acratocnus odontrigonus and Heteropsomys insulans 



Fig. 1. — Palatal view of rostral region of Acratocnus (11/3 X nat. size). 

 Fig. 2. — Palatal view of Heteropsomys, showing pattern of molar crowns (2 X 



nat. size). 

 Fig. 3. — Crown view of mandibular molar series of Heteropsomys (2 X nat. 



size) , 



