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.