FIGURE 1. Habitus of Dixa intacta, holotype. Scale bar equals 3 mm.

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FIGURE 2. Morphological features of Dixa intacta. 1, Antennae with individual flagellomeres delineated; 2, Dorsal aspect of the thorax. Scale bars equal 0.5 mm for both figures.

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FIGURE 3. Line drawings of wings. 1, Dixella intacta; 2, D. eomarginata; 3, D. curvistyla. Wing venation is from McAlpine (1981). Scale bar equals 1 mm.

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FIGURE 4. Tarsal claw teeth of the Kishenehn Dixella. 1, Dixella intacta left metatarsal claw; 2, D. curvistyla left metatarsal claw; 3, D. spinilobata right metatarsal claw. Arrows point to teeth. Scale bars equals 50 μm.

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FIGURE 5. The terminalia of Dixa intacta. 1, Posterior portion of abdomen including the spermatheca; 2, Cerci. Scale bars equal 0.5 mm (1) and 0.05 mm (2).

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FIGURE 6. Habitus of Dixella eomarginata, holotype. Scale bar equals 3 mm.

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FIGURE 7. Morphological features of Dixa eomarginata. 1, Wing with an emarginate posterior margin (arrowhead); arrows denote an apparent false vein posterior to vein M. 2, Terminalia. Scale bars equal 1.0 mm (1) and 0.25 mm (2).

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FIGURE 8. Habitus of Dixella curvistyla, holotype. Scale bar equals 3 mm.

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FIGURE 9. Morphological features of Dixella curvistyla. 1, Head and antennae; 2, Terminalia. The arrow points to the apical lobe of the gonocoxite. Scale bars equal 0.5 mm (1) and 0.2 mm (2).

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FIGURE 10. Habitus of Dixella spinilobata, holotype. Scale bar equals 3 mm.

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FIGURE 11. Morphological features of Dixella spinilobata. 1, Photograph of the terminalia; spiniform apical lobe marked with an arrow; 2, Line drawing of a partial reconstruction of the right portion of the terminalia (dorsal view). Scale bar equals 0.25 mm.

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FIGURE 12. Intraspecific wing venation pattern variability in Dixidae. 1-2, Wings from two different individuals of Dixella nova (USNM01193745, USNM01193785, ♀, ♂, respectively; NY). 3-4, Wings from two different individuals of Dixa terna (USNM01193791, USNM01193792, ♂, ♂, respectively; PA & VA). 5-6, Wings from two different individuals of Dixa rhathyme (USNM01193798, USNM01193868, ?, ♀, respectively; CA). 7-8, Wings from two different individuals of Dixella obscura (USNM01193908, USNM01193974, ?, ♀, respectively; AZ & AK). Collection localities are in parentheses. Arrows and arrowheads denote specific points of variation. Abbreviations: AK = Alaska, AZ = Arizona, CA = California, NY = New York, PA = Pennsylvania, VA = Virginia, USA.

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