Oh, I don't know. Wasn't paying a lot of attention. Some kind of emerger. The swallows were swooping low over the water too, scooping up something.What were the trout jumping at or does "match the hatch" mean that much?
I'd probably start by tossing a crippled callibaetis, twitching it gently while riding in the top film of the water. Have found that to be an excellent fly when "bugs" of some sort are rising to the surface and flying away.