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 Mesomelissa Engel , new subgenus ZooBank: urn:lsid:zoobank.org:act: BA59CDBC-93CC-4176-9468-18CCE8F2C0A3 TYPE SPECIES : Chalcobombus martialis Cockerell, 1908 ( sensu Engel, 2001a). DIAGNOSIS: This subgenus includes those species in which the basal vein (1M) is comparatively straight (distinctly arched in Eckfeldapis ) and is proximal to 1cu-a, while r-rs is well separated from 1Rs and with a normally developed pterostigma (pterostigma significantly reduced in Electrapis s.str . , r-rs and 1Rs close together on pterostigma in Eckfeldapis ), and 1m-cu meets the second submarginal cell at midlength or about 2/3 length. In addition, 2Rs is comparatively straight (rather than sinuate) and 2rs-m is comparatively close to 2m-cu, either confluent or separated by about 1–3× a vein width (except in E. tornquisti Cockerell where the separation is great, about 6–10× a vein width). ETYMOLOGY: The new subgeneric name is a combination of the Greek words mésos ( μέσος , “middle”) and mélissa ( μέλισσᾰ , “bee”). The gender of the name is feminne. INCLUDED SPECIES : Aside from the type species in Baltic amber, the subgenus includes E . ( Mesomelissa ) krishnorum Engel and E . ( M .) tornquisti in Baltic amber, E . ( M .) micheneri Wappler & Engel from the Eckfeld Maar, and one undescribed species from Green River.