Description. Head. anterior border of labrum concave, anterior angles rounded. Clypeus inclined, short (anterior-posterior), rectangular, anterior border linear slightly arcuate, anterior angles rounded and directed downward, smooth and brilliant. Frontoclypeal suture slightly arcuate. External tubercles distinct, rounded. Frontal area short, without inner tubercles. Frontal ridges poorly marked. Frontal fossae glabrous or with 1-2 setae. Median frontal structure of “falsus” type (see Reyes-Castillo 1970), center horn short with apex not free, without median longitudinal groove posteriorly; lateral ridges curved slightly forward, with terminal tubercles. Occipital groove well marked, terminating in supraorbital ridges. Anterior 1/2 of supraorbital ridge bituberculate, posterior 1/2 not bifurcate. Anterior cephalic angle rounded. Canthus not swollen distally, apex rounded, not, or barely, reaching lateral eye margin. Dorsal width of an eye 1/8 head width. Ligula between insertions of labial palps wide, convex or slightly convex. Lateral lobes of mentum with anterior external border rounded, whole surface punctate and pubescent, lateral border straight. Medial basal mentum bare without punctures, anterior border slightly biconvex. Hypostomal process narrow without lateral depression. Infraocular ridge indistinct, punctate and pubescent. Mandible with only 2 apical teeth. Mandibular tooth occupies more than 1/2 mandible length. Internal teeth bifid. Thorax. Lateral fossa of pronotum without punctations, 0-2 other punctations on lateral pronotum outside fossa. Arcuate (3 specimens) or linear (1 specimen) scars dorsally on posterior 1/3 of pronotum, 1 on each side. Pronotum with marginal groove very narrow; anterior angles rounded. Prosternum rhomboidal with posterior apex truncate.