Abstract

The genus Orchestoidea Nicolet, 1849 is geographically restricted to sandy beaches of the southeastern Pacific coast of Chile, being found from 23°S (Antofagasta, northern Chile) to 45°S (Guamblin Island, southern Chile), along a latitudinal gradient of ca. 2,400 km. Orchestoidea tuberculata Nicolet, 1849, the only known species for the genus, was originally described from Valparaíso Bay, central Chile (33°S). However, the published morphological descriptions are incomplete and a comparison with populations along the entire distributional range is difficult, because the type material is considered lost. In this paper, we selected a male specimen recently obtained from a site close to the type locality, to designate a neotype for O. tuberculata. A detailed description and illustrations of this specimen are also provided to establish a basis for further analysis of Orchestoidea.