ventral pair of sensory palps and a pair of organs on the neck. The peristomium is a ring, often hidden dorsally by the prostomium and the first segment
v. a basi sursum gradatim ampliatae et ± ciliatae, os subcirculare; peristomium magnum 1,5—2 cm latum, obliquum, postice in collum 3—5 cm altum elongatum