A outer face of the left maxilla of Cryptopone hartwigi; worker (CASENT0251956); Roman numerals indicate the count of maxillary palpomeres B outer face of the labium of Cryptopone hartwigi (CASENT0251956); Roman numerals indicate the count of labial palpomeres C expanded maxillolabial complex of Simopelta transversa in ventral view; worker (ANTWEB1008589); Roman numerals indicate the count of maxillary and labial palpomeres D maxillolabial complex of Thaumatomyrmex fraxini in ventroapical view; worker (ANTWEB1008597); Roman numerals indicate the count of maxillary and labial palpomeres E expanded maxillolabial complex of Parvaponera darwinii madecassa in ventral view; worker (CASENT0389498); Roman numerals indicate the count of maxillary and labial palpomeres F right metacoxal cavity of Platythyrea cribrinodis in ventral view; worker (CASENT0778160); arrowhead indicates the fused annular cuticle encircling the cavity externally G right metacoxal cavity of Myopias darioi in ventral view; paratype, worker (CASENT0810080); arrowhead indicates the fused annular cuticle encircling the cavity externally H right metacoxal cavity of Phrynoponera pulchella in ventral view; worker (CASENT0217034); arrowhead indicates the annular gap around the cavity F protibial apex and basal region of the probasitarsus of Loboponera obeliscata in posterior view; worker (ANTWEB1008545); arrowhead indicates the minute basoventral lamella of the calcar. Images by FA Esteves (A, B, E–H) and RA Keller (C, D, I); available at AntWeb.org. Scale bars: 0.02 mm (A, B, D); 0.03 mm (C); 0.04 mm (E–I).