PROC, US, NAT MUS. VOL. 110 



HERSHKOVITZ, PLATE 3 



Lateral aspect ( X 2) of same skulls (with mandibles) shown in plates 1, 2: a, Oryzomys 

 bicolor; b, 0. concolor; c, 0. palustris; d, Rhipidomys venuslus. 



