_Echimys albispinus_ Is. Geoffroy Saint-Hilaire, 25 June 1838, Comptes Rendus Acad. Sci., Paris, 6(26):886; Is. Geoffroy, August, 1838, Ann. Sci. Nat., Paris, 10 (ser. 2):125; Is. Geoffroy, 1840, Mag. Zool., Paris (ser. 2, année 2, livr. 13):33, 53, pl. 26, pl. 29 (figs. 1, 2, 3); Allen, 1899, Bull. Amer. Mus. Nat. Hist., 12(20):261. _Echinomys fuliginosus_ Wagner, 1843, Schreber's Säugethiere, suppl., 3:343. _Echimys albispinosus_ Waterhouse, Nat. Hist., Mammalia, 2:341. _Proechimys albispinus_ Allen, 1899, Bull. Amer. Mus. Nat. Hist., 12(20):264; Thomas, 1911, Ann. Mag. Nat. Hist., 8 (ser. 8):252. _Proechimys albispinus albispinus_ 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. _Type locality._--Ilha Madre de Deus, _Itaparica_ (near Salvador), Bahia, Brazil. _Type_: Museum d'Histoire Naturelle, Paris, no. A 7669, "skull ... practically perfect" (Thomas, 1921:142). _Range._--Island Madre de Deus, Macaco Seco, Andaraí and probably islands of the bay of Todos os Santos and valley of the Paraguassú River. _Diagnosis._--Aristiforms wide; color on setiforms Ochraceous-Tawny on upper parts and sides; incisors orthodont; molariform teeth with one counterfold, p4 rarely with two. _Pelage._--_Aristiforms on middorsal region_: Lanceolate aristiforms, with basal part whitish, gradually blackening toward tip; total length, 25 to 28 mm; maximum width, 1.2 mm; clavate aristiforms with base whitish, gradually blackening toward tip but interrupted by Ochraceous-Tawny, subapical zone. _Aristiforms on outer thighs_: Whitish on basal half, gradually blackening toward tip; total length, 24 to 26 mm; maximum width, 0.9 mm. Some are whitish basally, gradually blackening toward distal part but distal fourth or fifth near (15'_j_) Ochraceous-Tawny. _Setiforms on middorsal region_: Whitish basally, gradually blackening toward tip but interrupted by Ochraceous-Tawny, subapical zone; total length, 20 to 23 mm; maximum width, 0.1 mm. Some setiforms almost completely whitish. _Setiforms on outer thighs_: Whitish basally, gradually blackening toward tip but interrupted by near (15'_j_) Ochraceous-Tawny, subapical zone; total length, 18 to 20 mm; maximum width, 0.06 mm.