ZYGOMELON-ZODION, A NEW GENUS AND SPECIES OF BATHYAL VOLUTE FROM NEW-ZEALAND

Zygomelon zodion, a new genus and species of Volutidae, is described f rom bathyal depths on the Bounty Plateau in the Bounty Trough, southea stern New Zealand. It is referred to the tribe Alcithoini of the subfa mily Zidoninae on the basis of anatomical and radular features. Zygome lon zodion can most easily be distinguished from species of Alcithoe H . & A. Adams, 1853, by the presence of two rather than four or more co lumellar folds. Conchological similarities between Zygomelon and the g enus Miomelon Dall, 1907, of the subfamily Odontocymbiolinae lead us t o hypothesize that the subfamily Odontocymbiolinae differentiated from the zidonine tribe Alcithoini in the Wedellian Province during the Pa leogene.