MORPHOLOGY AND SYSTEMATICS OF THE ENIGMATIC VOLUTID PLICOLIVA-ZELINDAE (PETUCH, 1979) (MOLLUSCA, GASTROPODA)

The morphology of the living animal, anterior alimentary system and ne rvous system of Plicoliva zelindae is described. Presence of paired si phonal appendages, broad cephalic shield and lateral lappets, as well as a long connective between the supraesophageal and right pleural gan glia confirm the assignment of this taxon to the family Volutidae. The subfamily Plicolivinae, characterized by its multicuspid lateral teet h, distinctive sabot-like rachidian teeth, and a gland of Leiblein wit h greatly enlarged terminal bulb, shares some anatomical features with the volutid subfamilies Haliinae and Volutinae. With certain members of the former (e.g., Amoria) it shares a distinctive external pigmenta tion pattern and similar siphonal appendages and rachidian teeth. Comp arisons of Plicolivinae with published data on various species of Volu tinae reveal similar shell morphology and the presence of a gland of L eiblein with an enlarged terminal bulb in both subfamilies.