Diagnosis: Possess the following unique characters: presence of a vomer-palatine organ; neural complex of Weberian apparatus in direct contact with supraoccipital region of skull; a terete process of basioccipital bone; a superficial labial fold (or lower lip) developed posterior to lower jaw; a rostral fold papillose with a greatly crenulated distal margin, disconnected with lower lip at corner of mouth; a lower lip separated from lower jaw by a groove extending along entire lower jaw, with a free anterior margin exteriorly papillated; a lower jaw covered with a thick, cornified sheath, with a sharp margin; mouth inferior, slightly arch-shaped; two pairs of minute barbels; pharyngeal teeth triserial (ref. 57027).