The posteromedian portion of the head lacking 1-3 simple eyes consisting of single beadlike lens. Used in Antkey to distinguish among formicine species. The character is not always reliable, however, and should be used with caution.
Scratchpads developed and conceived by (alphabetical):
Ed Baker,
Katherine Bouton
Alice Heaton
Dimitris Koureas,
Laurence Livermore,
Dave Roberts,
Simon Rycroft,
Ben Scott,
Vince Smith