Distribution & Ecology: Society (Tahiti) - Marine; Shoreline to 10 m; ?Hard bottom.

Regional Records: Macromedaeus distinguendus - Kim, 1973: 630 (Distribution only, Tahiti). - Guinot, 1985: 451 (Society; List). - Poupin, 1996a: 49, 77 (Checklist). - Remark: Guinot (1985) has listed this species after Forest & Guinot (1961). These authors have actually examined some Xantho distinguendus de Haan, 1835 (p. 57, under Medaeus noelensis Ward, 1934), but they are from Hong Kong. It could be that Guinot refers to Kim (1973), who has quoted "Tahiti" in the distribution of this species. However, this location concerns neither the material examined, nor one of the references cited by Kim under Macromedaeus distinguendus. The presence of this species in French Polynesia remains thus doubtful.