New genera of melikertine bees with facial modifications in Baltic amber (Hymenoptera: Apidae) Author Engel, Michael S. Division of Entomology, Natural History Museum and Department of Ecology & Evolutionary Biology, 1501 Crestline Drive - Suite 140, University of Kansas, Lawrence, Kansas 66045 - 4415, USA (msengel @ ku. edu). & Division of Invertebrate Zoölogy, American Museum of Natural History, Central Park West at 79 Street, New York, New York 10024 - 5192, USA (mengel @ amnh. org, sdavis @ amnh. org). Author Davis, Steven R. Division of Entomology, Natural History Museum and Department of Ecology & Evolutionary Biology, 1501 Crestline Drive - Suite 140, University of Kansas, Lawrence, Kansas 66045 - 4415, USA (msengel @ ku. edu). text Journal of Melittology 2021 2021-07-06 2021 103 1 52 http://dx.doi.org/10.17161/jom.i103.15655 journal article 10.17161/jom.i103.15655 2325-4467 13146053 Key to Species of Ctenoplectrella (modified from Gonzalez & Engel, 2011) 1. Forewing 2rs-m arched apically in posterior half, thus second submarginal cell more strongly produced toward wing apex along posterior margin; medioapical margin of clypeus straight (shape of clypeus unknown in C . phaeton ) ........ 2 —. Forewing 2rs-m relatively straight and therefore second submarginal cell not more strongly produced toward wing apex along posterior margin; medioapical margin of clypeus gently convex [Baltic amber] ........... C . viridiceps Cockerell Figure 76. Lower view of head of holotype female of Ctenoplectrella eocenica (Michez & Nel) , new combination (PA 3190 1/17). Photograph courtesy V. Ngô-Muller. 2(1). Forewing basal vein confluent with cu-a; first submarginal cell shorter than second submarginal cell ............................................................................................ 3 —. Forewing basal vein distad cu-a; first submarginal cell as long as or longer than second submarginal cell ............................................................................................ 6 3(2). Mesepisternum impunctate laterally; metasomal terga faintly imbricate .......... 4 —. Mesepisternum with coarse, faint punctures laterally; metasomal terga with small, scatered punctures ......................................................................................... 5 4(3). Propodeal setae long, erect, and branched; tarsal setae fuscous; gena tapering in width from widest above to narrower below [ Rovno amber] ........................... .................................................................................. C . zherikhini Engel & Perkovsky —. Propodeal setae scatered, short, and simple; tarsal setae white or off-white; gena of relatively equal width along its length [Baltic amber] .............................. ........................................................................................................... C . grimaldii Engel 5(3). Metepisternum punctate; body pubescence distinctly short and sparse [Baltic amber] .......................................................................... C . phaeton Gonzalez & Engel —. Metepisternum impunctate; body pubescence of moderate length, not distinctly short and sparse [Baltic amber] ................................................ C . cockerelli Engel 6(2). First submarginal cell as long as second submarginal cell; pleura punctate [Oise amber] .............................................................................. C . eocenica (Michez & Nel) —. First submarginal cell longer than second submarginal cell; pleura impunctate [Baltic amber] ..................................................................................... C . gorskii Engel