_Diagnosis._--Aristiforms wide and stiff; tail 96 per cent of head and body; color on setiform Cinnamon-Buff; incisive foramen short and moderately wide; vomerine sheath complete; all molariform teeth with two counterfolds. _Pelage._--_Aristiforms on middorsal region_: Gray basally, gradually blackening toward tip; total length, 24 to 26 mm; maximum width, 1.3 mm. _Aristiforms on outer thighs_: Gray basally, gradually blackening toward middle, and distal parts near (15''_c_) Pinkish Cinnamon; total length, 18 to 20 mm; maximum width 0.8 mm. _Setiforms on middorsal region_: Gray basally, gradually blackening toward tip but interrupted by Cinnamon-Buff, subapical zone; total length 14 to 16 mm; maximum width, 0.06 mm. _Skull._--Slender; bullae large and well-inflated; jugals with conspicuous, transverse ridge; postorbital process of zygoma moderately developed and involving only squamosal; incisive foramen short and narrow (4.1 × 2.1 mm); vomerine sheath complete, with maxillary part short and thick; mesopterygoid fossa extending forward as far as posterior parts of second molars; posterior palatine foramina at plane of premolars. [Illustration: FIG. 128. Map showing the geographic ranges of the subspecies of _Proechimys iheringi_.] _Teeth._--Upper and lower molariform teeth with two counterfolds. Counterfolds coalesced in P4 and M1 of one specimen. _Comparisons._--From _P. i. gratiosus_ and _P. i. panema_, _paratus_ differs in: all molariform teeth with two, instead of some with fewer, counterfolds; vomerine sheath complete and thick instead of usually incomplete; incisive foramen shorter and narrower; aristiforms conspicuously wider; setiforms Cinnamon-Buff instead of Ochraceous-Buff and Cinnamon, respectively. Tail 96 per cent of head and body in _paratus_ instead of 100 per cent as in _panema_. _Remarks._--The animals were captured in climax forest. _Specimens examined._--Total number, 3 (MN), from Brazil, Espirito Santo, _Santa Teresa_, Floresta da Capela de São Braz; altitude 630 meters. Proechimys setosus (Desmarest)