Crematogaster (Crematogaster) jacobsoni Forel

Crematogaster jacobsoni Forel, 1911b: 201 .

Three syntype workers from INDONESIA: Semarang, Java (MHNG) and one syntype worker (NHMB) [examined] .

Combination in C. ( Orthocrema) by Emery, 1922: 132; in C. ( Acrocoelia) by Santschi, 1928: 34; in C. ( Mesocrema) by Santschi, 1937: 310.

Remarks. Examination of syntype workers in MHNG and NHMB reveals that C. jacobsoni is not similar to the C. brevis group or C. treubi group in Asia. Characteristic features include: occipital carinae developed; petiole weakly broader anteriorly, but without angular corners; postpetiole weakly bilobed with longitudinal median sulcus.

This species is similar to C. (C.) semperi Emery, 1893 or C. (C.) simoni Emery, 1893 . We hereby transfer C. jacobsoni to the subgenus Crematogaster, to compare it with closely related species in this group in the future.