MACROGEOMYS. 327 
frontal flat, depressed medianly, broad: postorbital processes large; 
palato-pterygoids short, broad, truncate posteriorly: braincase high 
above root of zygoma; lambdoid crest straight: ox cipital plane flat, 
sloping forward; upper premolar with four enamel plates; first upper 
and second lower molars with two enamel plates each: last upper 
molar with lengthened heel and deep outer sulcus: upper incisor with 
only one narrow deep sulcus on inner third of face. 
Fic. 62. MACROGEOMYS CHERRII. 
No. 9070 Am. Mus. Nat. Hist. Coll. Nat. size 
