Revision of type and non-type material assigned to the genus Orthocladius by Goetghebuer (1940 - 1950), deposited in the Royal Belgian Institute of Natural Sciences (Diptera: Chironomidae) Author Magoga, Giulia ) &) &) Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali (DISAA), via Celoria 2, I 20133, Milano, Italia; e-mails: giulia. magoga @ unimi. it; matteo. montagna @ unimi. it Author Montagna, Matteo ) &) &) Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali (DISAA), via Celoria 2, I 20133, Milano, Italia; e-mails: giulia. magoga @ unimi. it; matteo. montagna @ unimi. it Author Marziali, Laura ) &) Water Research Institute, National Research Council (IRSA-CNR), Via del Mulino 19, I 20861 Brugherio (MB), Italy; e-mail: marziali @ irsa. cnr. it Author Rossaro, Bruno ) &) Università degli Studi di Milano, Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente (DeFENS), Via Celoria 2, I 20133 Milan, Italy; e-mail: bruno. rossaro @ unimi. it Author Disaa text Acta Entomologica Musei Nationalis Pragae 2017 Acta. Ent. Mus. Natl. Pragae 2017-12-31 57 2 723 749 http://dx.doi.org/10.1515/aemnp-2017-0097 journal article 10.1515/aemnp-2017-0097 0374-1036 5318416 638421F2-985E-43CC-8438-E871F96B1DB8 Orthocladius corax (Kieffer, 1924) ( Figs 47‒52 ) ? Orthocladius corax Kieffer, 1924: 65 . Material examined. 1 ♁ in isinglass,now mounted on slide, labelled ‘ Orthocladius corax // locality Silésie 23.III.1944 // ex. coll. Bettinger, Belg. I. G. 12.595’. Comments. ASHE & O’CONNOR (2012) listed Orthocladius corax Kieffer, 1924 among nomina dubia in Orthocladiinae . The bare eyes, the fine wing punctuation, squama with setae, presence of acrostichals, absence of pulvilli, the presence of an anal point rounded at the apex suggest inclusion of the species in Hydrobaenus Fries, 1830 . Figs 47‒52. Hydrobaenus corax (Kieffer, 1924) . 47 ‒ pulvilli, 48 ‒ hypopygium, 49 ‒ anal point, 50 ‒ virga, 51 ‒ inferior volsella, 52 ‒ gonostylus. The species appears to be valid based on specimens examined, however the material examined is non-type material, even if it comes from the type area (Silésie), but being collected twenty years later. At present it cannot be ascertained whether Goetghebuer’s identification of the RBINS specimen is correct or a misidentification of O. corax .