Echinomys fuliginosus [Wagner], 1843, Schreber's Säugethiere, suppl. 3:343; [Wagner], 1844, Schreber's Säugethiere, suppl. 4, pl. 39 D.
Proechimys setosus [Allen], 1899, Bull. Amer. Mus. Nat. Hist., 12(20):264; [Thomas], 1921, Ann. Mag. Nat. Hist., 8 (ser. 9):141; [Tate], 1935, Bull.
Amer. Mus. Nat. Hist., 68(5):401; [Ellerman], 1940, The families and genera of living rodents, Brit. Mus. (Nat. Hist.), 1:122.
Proechimys fuliginosus [Tate], 1935, Bull. Amer. Mus. Nat. Hist., 68(5): 400; [Ellerman], 1940, The families and genera of living rodents, Brit. Mus. (Nat. Hist.), 1:119.
Type locality.—Unknown; see remarks under P. setosus. Type: Museum d'Histoire Naturelle, Paris, no. A. 7787 ([Thomas], 1921:141), "very imperfect."
Diagnosis.—Aristiforms wide; P4 and M1 with two counterfolds; p4 with two counterfolds, one anterior to main fold.
Pelage.—Aristiforms on middorsal region: Gray basally, gradually blackening toward tip; total length, 18 to 20 mm; maximum width, 0.8 mm. Aristiforms on outer thighs: Color much faded; total length, 15 to 17 mm; maximum width, 0.3 mm. Setiforms on middorsal region: Color faded; total length, 16 to 18 mm; maximum width, 0.04 mm. Setiforms on outer thighs: Color faded; total length, 10 to 13 mm; maximum width, 0.03 mm.
