ABSTRACT
Head short to weakly prolonged, without a true rostrum, hypognathous, exerted, broadly exposed in dorsal view; occipital region weakly to strongly constricted; surface smooth to densely, deeply punctate; front without distinct grooves; antennal calli weak, well separated; gular sutures evident at hind margin of cranium, separate. Eyes large, lateral, protuberant, strongly protuberant and weakly stalked in some species, coarsely or finely faceted; interior margin of each eye with emargination ranging from broad and shallow to narrow, sharply angled and deep. Antenna with eleven freely articulated antennomeres, short to moderate in length, extending to point just beyond humerus (in Palophaginae long and filiform, reaching middle of elytra or just beyond in some species), antennomeres 5-11 subserrate; insertion lateral, low on face, between eye and base of mandible, internally delimited by elevated flange in some Megalopodinae. Mouthparts exposed behind, free from prosternum; labrum distinct; clypeus subquadrate to transverse, projecting slightly or deeply between base of mandibles, well delineated from frons; man-
dible long, apically narrow, evenly curved with acute, unidentate apex, or bidentate in Zeugophorinae (exceptionally long and bladelike in Megalopodinae with apices broadly overlapping in repose), without mola in most species, with distinct mola in Palophaginae. Maxilla with large galea and lacinia, each with dense brush of setae; palp 4-segmented, not asymmetrically dilated; palpomeres long and slender, moderate in length in Zeugophorinae; terminal palpomere cylindrical, with apex evenly rounded or angularly truncate. Mentum transverse, not large; ligula large, membranous, deeply bilobed in most species, small and not distinctly lobed in Zeugophorinae; labial palp 3-segmented.
