NEOTYPE DESIGNATION AND RE-DESCRIPTION OF THE VANISHING TREE SNAIL, AMPHIDROMUS (AMPHIDROMUS) MUNDUS (PFEIFFER, 1853)(PULMONATA: CAMAENIDAE)

摘要

A population of Amphidromus (Amphidromus) mundus (Pfeiffer, 1853) was recently discovered on a Malaysian island in the South China Sea. Here we investigate and describe its internal anatomy for the first time, and its shell is also re-described. The small, white, chirally dimorphic shells with a reflected lip that is not attached to the outer wall, as well as its pale brown body colour allow clear discrimination from the related species A. (A.) perversus, A. (A.) inversus albulus, and A. (A.) atricallosus. The distinctively long epiphallic caecum provides a clear discriminating character in genital anatomy. Type material could not be traced and a neotype is designated herein for nomenclatural stability.