The Ants (Hymenoptera: Formicidae) of Bol’shaya Svetlovodnaya (Late Eocene of Sikhote-Alin, Russian Far East) Author Dlussky, G. M. Author Rasnitsyn, A. P. Author Perfilieva, K. S. text Caucasian Entomological Bulletin 2015 11 1 131 152 journal article Gesomyrmex incertus sp. n. ( Fig. 14 ) Material. Holotype PIN 3429/1183, PIN 3429/1164 (counterprint of the same specimen), head of gyne. Description. Gyne. Head subrectangular, 1.5 times longer than wide, with nearly parallel sides, rounded occipital corners and concave occipital margin. Anterior clypeal margin projected as rounded lobe. Eyes oval, situated on the midlength of head; head 3.8times longer than maximum eye diameter. Mandible massive, triangular, with acute apical tooth and small blunt denticles on the masticatory margin. Measurements of holotype, mm: HL2.4; HW1.6; ED0.65. Comparison. Differs from all known species of Gesomyrmex by combination of elongate head with concave occipital margin and position of eyes. Notes. In spite of key characters of genus not preserved, preserved head of described specimen in general habitus is most similar to known species of Gesomyrmex . That is why we placed it to this genus. Etymology. Incertus is the Latin for doubtful.