Lloyd, that's great getting another one identified to species. Next year I'll try to catch one of these for Don to have a look at, and erase any doubt of the species.

I reasonably sure that this is Paragnetina media. (And I suspect that might have been Donald's thought as well.) Most of the really dark-winged large Northeastern perlids are either Paragnetina or Agnetina, and all but media usually show a fair amount of contrasting color on the head, legs, or elsewhere.

P. media is rather common and widespread, and seems to tolerate conditions that are less than optimal for some other perlids. The Stark, et al. nickname, "Embossed Stone," might refer to the deep rugose pattern on the pronotum, but I'm not sure about that.

This was the biggest stonefly I've come across so far. Would a larger picture help? If so I can post a large image on mt pbase site.

I think I know what it is, but am not sure enough to say it.