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 ( Euorthocladius ) tolleti Goetghebuer, 1944 , stat. nov. ( Figs 20–23 ) Orthocladius tolleti Goetghebuer, 1944: 39 . Type material examined. Orthocladius tolleti : HOLOTYPE : ♁ pinned, now mounted on slide, labelled ‘ Orthocladius tolleti n. sp. // type ♁ / M. Goetghebuer // type locality Onoz-Spy , 14.V.1942 , R . Tollet legit // R .I.SC.N.B. 18.073 / Coll. et det. M. Goetghebuer’ . Figs 20‒23. Orthocladius ( Euorthocladius ) tolleti (Goetghebuer, 1944) . 20 ‒ anal point, 21 ‒ virga, 22 ‒ inferior volsella, 23 ‒ gonostylus. Comments. Only the last three abdominal segments and the genitalia are preserved. A detailed examination of the hypopygium shows that it belongs to the subgenus Euorthocladius Thienemann, 1935 , but it does not fit with any other known species. ASHE & O’CONNOR (2012: 703) listed the name among nomina dubia in Orthocladiinae ; despite the specimen being in very poor condition, it is considered a valid species.