Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
I found this specimen in the same collection as a similar one. Since I only have strange views of this one, it's possible that they're actually the same specimen and I somehow confused my picture-ordering and got the impression that they're different nymphs.
This mayfly was collected from the Namekagon River in Wisconsin on June 8th, 2005 and added to Troutnut.com by Troutnut on May 26th, 2006.