Zacotus matthewsii LeC. (matthewsi auct.) is a rare beetle that lives in damp situations under cover in timbered areas in the Pacific Northwest. LeConte, Ann. Mag. Nat. Hist. (4) IV, 1869, p. 373-374, described it from a unique female from Vancouver Island. Horn, Trans. Ent. Soc. IX, 1881, p. 169, listed it from Washington; Leng, Cat. Col. Am. n. of Mex. 1920, p. 68, listed it from “No. Cal.”; Casey, Mem. Col. IX, 1920, p. 290-291, cited specimens from Moscow in northern Idaho and Clackamas Co. in northwestern Oregon; and Van Dyke, Pan-P. Ent. II, 1925, p. 95, from the Bitter Root Mountains of extreme western Montana.