This one seems to lead to Couplet 35 of the Key to Genera of Perlodidae Nymphs and the genus Isoperla, but I'm skeptical that's correct based on the general look. I need to get it under the microscope to review several choices in the key, and it'll probably end up a different Perlodidae.
Anal vein: The anal veins (denoted 1A through 5A in caddisflies) are longitudinal veinsposterior to the cubitus. Caddisfly forewings have 3 anal veins, which typically coalesce into a single vein reaching the wing margin, forming a characteristic forked shape. Caddisfly hind wings have 1 to 5 anal veins, which all reach the wing margin.
These other words reference the same concept: anal veins, vein 1A, 1A vein, 1A, vein 2A, 2A vein, 2A, vein 3A, 3A vein, A3, vein 4A, 4A vein, A4, vein 5A, 5A vein, A5.
