Maxillae
Homology Weekly: Mouthparts

Frontal part of the head in an Anochetus emarginatus worker, profile view (Scanning Electron Micrograph, Roberto Keller/AMNH)
This image shows the mouthparts of a trap-jaw ant in resting position. The only structures really visible are the prominent elongated mandibles (in yellow) that project forward. The rest of the pieces, laying immediately below, are retracted inside the preoral cavity.