Abstract
Subsequent to my 1983 review of the North American species of Lithurge, the type specimen of L. planifrons (Friese) has been examined: it is a senior synonym of L. socorroensis (Mitchell) (NEW SYNONYMY). The species that I incorrectly believed to be L. planifrons is here described as L. bitorulosa, no prior name being available. A corrected key to the North American species is included.