Skull.—Slender; bullae small but well-inflated; upper edge of jugals deeply concave; transverse ridge of jugals conspicuous; postorbital process of zygoma small, involving only squamosal; incisive foramen elongate (5 x 2.5 mm); vomerine sheath almost always incomplete, and maxillary part lacking or, when present, slender; mesopterygoid fossa extending forward as far as middle of second molars; posterior palatine foramina at plane of front border of first molars or slightly anterior thereto.
Teeth.—Upper molariform teeth with two counterfolds in 10 of 16 specimens and only one in remainder; these folds commonly coalesced; M3 with only one counterfold in 6 specimens, and 2 counterfolds in remainder. Lower molariform teeth with two counterfolds in 6 specimens and in 10 of them m3 has only one counterfold.
Comparisons.—From P. i. panema, gratiosus differs in: Lower molariform teeth with only one counterfold in smaller percentage of specimens; incisive foramen shorter; aristiforms narrower; setiforms Ochraceous-Buff instead of Cinnamon. Differences from iheringi and paratus are given in the accounts of those subspecies.
Remarks.—All the animals were captured in climax forest.
Specimens examined.—Total number, 16 (MN), from Brazil, Espirito Santo, Santa Teresa, Floresta da Caixa Dagua, altitude 750 meters.
Proechimys iheringi panema subspecies nova
Type locality.—Campinho, Colatina, Espirito Santo, Brazil; altitude 500 meters. Type: Museu Nacional, no. 8288, adult female; collected on 15 July, 1942, by C. Lako.
Range.—Known only from the type locality.
Diagnosis.—Aristiforms moderately wide; tail of approximately same length as head and body; setiforms Cinnamon; incisive foramen moderately long and narrow; vomerine sheath incomplete; upper molariform teeth with two counterfolds, but m3 most frequently with one.
Pelage.—Aristiforms on middorsal region: Gray basally, gradually blackening toward tip; total length, 21 to 23 mm; maximum width, 0.8 mm. Aristiforms on outer thighs: Gray, some gradually blackening toward tip and others with distal part Cinnamon; total length, 17 to 19 mm; maximum width, 0.7 mm. Setiforms on middorsal region: Gray, gradually blackening toward tip, but interrupted by Cinnamon, subapical zone; total length, 18 to 20 mm; maximum width, 0.06 mm. Setiforms on outer thighs: Gray, gradually blackening toward middle, and Cinnamon on all of distal parts or with tip blackish; total length, 13 to 15 mm; maximum width, 0.09 mm.