Early Eocene snakeflies (Raphidioptera) of western North America from the Okanagan Highlands and Green River Formation Author Archibald, S. Bruce 0000-0002-4397-2497 Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, V 5 A 1 S 6, Canada. https: // orcid. org / 0000 - 0002 - 4397 - 2497 & Museum of Comparative Zoology, 26 Oxford Street, Cambridge, Massachusetts, 02138, United States of America & Royal British Columbia Museum, 675 Belleville Street, Victoria, British Columbia, V 8 W 9 W 2, Canada Author Makarkin, Vladimir N. Federal Scientific Centre of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, Vladivo- text Zootaxa 2021 2021-04-01 4951 1 41 79 journal article 7413 10.11646/zootaxa.4951.1.2 d7a40f10-4145-499c-97be-3f9bc5088d2f 1175-5326 4655625 557825A0-714A-426A-917F-1C9AB7372C30 Raphidiidae genus and species A Fig. 18 Material. UWBM 74306, collected by Wesley Wehr in 2003, deposited in the UWBM collections. An incomplete folded forewing. Locality and horizon. Tom Thumb Tuff Member of the Klondike Mountain Formation, exposure B4131, Republic, Washington , U.S.A. ; early Eocene (Ypresian). Description. Forewing 9.3 mm as preserved (estimated complete length approximately 11 mm ). Costal, subcostal spaces not preserved. Pterostigma partially preserved, well pigmented. Two RA branches (none detected within pterostigma); one long forming distal margin of pterostigma; other short distad pterostigma; neither forked. Portion of RA distad pterostigma relatively long, terminates halfway between pterostigma, apex. RA space with two crossveins forming two radial cells (distal slightly shorter than proximal); 3ra-rp located in distal part of pterostigma along RA. RP with four pectinate branches: anterior trace shallowly forked; RP1 deeply forked, its anterior branch incompletely preserved, posterior branch forked again; RP2 about basal half preserved; RP3, RP4, each forked once. One long intraradial crossvein rp1-rp2 between stems of RP, RP1. Two crossveins between RP, MA detected (1r-m, 2r-m) connecting stem of RP, MA. M forked well proximad origin of RP. MA deeply dichotomously forked twice. MP zigzagged, anterior trace simple terminally with two simple branches; proximal branch originating from terminal point of MP+CuA. Two intramedian crossveins form two doi , equal in length. Anterior trace CuA strongly zigzagged, fused with MP for relatively long distance to form part of posterior margin of basal doi , with one long simple branch. CuP simple. Crossvein icu between CuA, CuP long. Crossvein between CuP, AA1 fragmentary preserved. Remarks. The specimen has typical venation for Raphidiidae (see Makarkin & Archibald, 2014 ). Its forewing venation differs from that of all other species from the Okanagan Highlands by relatively short branches of MP, however we decline to name it as its venation lacks such important character as ScP and the costal space, and the pterostigma is incomplete.