Head shield extensive and granular, supraoccipital process granular; dorsomedian head groove narrow and deeper posteriorly. Eye 6 to 8 times in head length. Snout rounded, moderately long, 3 times eye diameter. Band of upper jaw teeth 4 to 5 times longer (across mouth) than broad (width of band); palatal teeth in 2 oval-oblong patches, 1 on each side, placed well forward on palate and usually parallel to each other, extensive; palatal teeth molariform. No filament on dorsal fin; dorsal-fin spine strong and stout, 1/2 to 2/3 of head length; pectoral-fin spine slightly longer and stronger, strong serrae along its hind margin; anal-fin rays 18 or 19. Adipose-fin base 2/3 of dorsal-fin base. Colour: purplish above, white below; fins dusky; adipose fin with blackish spot.