Liometopum microcephalum var. occidentale Emery, 1895d: 330 (w.m.) U.S.A. (California). Nearctic.

Primary type information: Primary type material: syntype workers (number not stated), 1 syntype male. Primary type localities: workers U.S.A.: California, San Jacinto (no collector’s name) (invalid restriction of type locality by Creighton, 1950a: 339; no lectotype designated); male U.S.A.: California, Mariposa (no collector’s name). Primary type depositories: MCZC, MSNG. Type notes: Creighton, 1950a: 339, records that part of the type series is in MCZC, which Shattuck, 1994: 130, cites as 1 worker, 1 male syntypes.