Cesare Dalfreddo (1972–2009) in memoriam
In recent years two interpretations of Arion alpinus Pollonera 1887 have been proposed: a valid species with a central European distribution or a junior synonym of Arion intermedius Normand 1852. Study of the original description and topotypes collected in the only precise Piedmontese locality mentioned by Pollonera (1887), Rivarossa Canavese, demon¬strate that the second is correct. To prevent Pollonera’s species from continuing to be misinterpreted, a neotype of A. alpinus is designated from among these topotypes. The neotype clearly belongs to A. intermedius so the names are synonyms.
Arion obesoductus Reischütz 1973, sometimes considered a synonym of A. alpinus, was described from juvenile speci¬mens from Austria. Although a new study of adult topotypical specimens is desirable, anatomical re-examination of a paratype revealed characters typical of A. alpinus auctt. non Pollonera 1887, namely a long oviduct and a flat epiphallus papilla. These characters are also evident in adult specimens from Italy. The name A. obsesoductus is thus reinstated for Arion alpinus auctt. non Pollonera 1887, a species of several countries in Central Europe.