Just read all the other comments. Yes the three species of Drunella were synonymized as lata, and then reinstated several months ago in an excellent paper by Dave Funk et al. They are easily separable by head and leg characters, by seasonality, and to a certain extent by stream sizes (Lloyd Gonzalez discusses this also - I haven't really seen them in our bigger rivers here). From this photo by Jonas, it actually looks like it could be cornutella due to the short hindtibiae. However, all of the 600 specimens we took out of this area this year were D. cornuta, and I believe that the legs are just foreshortened due to their angle in the photograph. D. cornuta is very typical of our smaller, colder mountain streams. D. lata likes more open, larger, warmer streams, and D. cornutella likes streams intermediate to these two extremes, mixing at times with one or the other species. I have made a mental note to photograph D. lata next year now.