Rostral fold or cap crenulated, covered densely with papillae, laterally connected with lower lip at corners of mouth. Upper lip greatly reduced or vestigial, with many tiny papillae arranged in a longitudinal row on upper jaw. Upper jaw bearing a thick, flexible, cornified sheath entirely covered by pendulous rostral fold, and laterally connected with lower lip by a frenum at corner of mouth. Lower lip anteriorly separated from lower jaw by a deep groove. Inner surface and anterior edge of free anterior part of median plate of lower lip densely covered with tiny papillae, regularly arranged in many transverse rows. Median plate of lower lip nearly round with a slightly papillose, round posteromedian patch. Lower jaw bearing a thick, cornified cutting edge.