[Illustration: FIGS. 122, 123. _Proechimys iheringi panema_, female, MN no. 8288, Campinho. Type. × 1.] [Illustration: FIGS. 124, 125. _Proechimys iheringi denigratus_, male, MN no. 8500, Mata do Ribeirão da Fortuna. Type. × 1.] [Illustration: FIGS. 126, 127. _Proechimys iheringi paratus_, female, MN no. 4012, Floresta da Capela de São Braz. Type. × 1.] =Proechimys iheringi iheringi= Thomas _Proechimys iheringi_ Thomas, August, 1911, Ann. Mag. Nat. Hist., 8 (ser. 8):252 (orig. descr.); Thomas, 1921, Ann. Mag. Nat. Hist., 8 (ser. 9):141; Tate, 1935, Bull. Amer. Mus. Nat. Hist., 68(5):400; Ellerman, 1940, The families and genera of living rodents, Brit. Mus. (Nat. Hist.), 1:122. _Type locality._--Island of São Sebastião (off São Paulo), Formosa, São Paulo, Brazil. _Type_: British Museum (Nat. Hist.), no. 2.8.25.5, adult male, presented by the São Paulo Museum. _Range._--Littoral and islands of São Paulo and Rio de Janeiro. _Diagnosis._--Aristiforms narrow; tail shorter than head and body; setiforms Cinnamon-Buff; incisive foramen short; vomerine sheath complete; upper molariform teeth with two or three counterfolds; lower molariform teeth with two counterfolds, rarely one in m3. _Pelage._--_Aristiforms on middorsal region_: Gray basally, gradually blackening toward tip; total length 18 to 23 mm; maximum width, 0.6 mm. _Aristiforms on outer thighs_: Gray basally, blackening distally toward tip; some differentiated with Cinnamon-Buff tip. _Setiforms on middorsal region_: Gray basally, gradually blackening toward tip but interrupted by a Cinnamon-Buff, subapical zone 3 mm long; total length, 16 to 20 mm; maximum width, 0.06 mm. _Setiforms on outer thighs_: Gray basally, gradually blackening toward tip but interrupted by Cinnamon-Buff, subapical zone or with Cinnamon-Buff continuous to tip. _Skull._--Slender; bullae small and well inflated; jugal dorso-ventrally wide with transverse ridge inconspicuous; incisive foramen short, 3.5 × 2.5 mm; vomerine sheath complete; mesopterygoid fossa extending forward as far as middle parts of second molars; postorbital process of zygoma small, formed by both jugal and squamosal; posterior palatine foramina at plane of premolars; interorbital breadth narrow. _Teeth._--Upper molariform teeth with two or three counterfolds (when unworn usually three and rarely four); sometimes only one counterfold in M3 and sometimes counterfolds fused in molars. Lower molariform teeth with two counterfolds, rarely one in m3.