PLATYGEOMYS 3) 
7 
oblique plate; anterior border of mesethmoid rounded above; upper 
premolar with three enamel plates; first and second upper molars 
with only one each; a single sulcus on upper incisor near median line. 
Fig. 58. PLATYGEOMYS GYMNURUS 
No. 45611 U. S. Nat. Mus. Coll. Nat. size 
