Monacoa Whitley [G. P.] 1943:171 Fem. Opisthoproctus grimaldii Zugmayer 1911. Type by being a replacement name. Replacement for Grimaldia Chapman 1942, preoccupied by Grimaldia Chevreux 1889 in Crustacea. •Synonym of Opisthoproctus Vaillant 1888 -- (Cohen 1973:156 [ref. 6589]). •Valid as Monacoa Whitley 1943 -- (Poulsen et al. 2016:9 [ref. 34664]). Current status: Valid as Monacoa Whitley 1943. Opisthoproctidae.