Couplet 83

83a:  Labrum not distinct, membranous and often hidden beneath clypeus; abdomen with paired glandular openings on lateral edge of tergites; tarsomere 4 with bifid ventral lobe

Cantharidae   p. 424

83b:  Labrum distinct and sclerotized; abdomen lacking paired glandular openings on tergites; tarsomeres 3 and 4 with bifid ventral lobes