The
anatomical line that is perpendicular to the
median anatomical line and is the tangent at the distalmost point(s) of the
clypeus in frontal view.
written by: Csősz, S., J. Heinze, and I. Mikó. 2015. Taxonomic Synopsis of the Ponto-Mediterranean Ants of Temnothorax nylanderi Species-Group. PLoS ONE 10:e0140000.