Head shield rugose and granulated from middle of or near posterior margin of orbit to supraoccipital process; supraoccipital process longer than broad at base with a median keel, its hind end nearly straight; median longitudinal groove deep, long, reaching base of supraoccipital process; predorsal plate V-shaped; premaxillary band of teeth on upper jaw 4 to 6 times as long as broad, mandibulary band of teeth on lower jaw deeply curved and narrowly interrupted; palate teeth granular or molarlike. in a single large, fully elliptical or semioval patch on each side.