These may fly larvae were common in the cool, clear, rocky ephemeral stream I was sampling. They were active on sunny flat surfaces, but were also found under rocks. Occasionally, they would do a funny tail pumping motion when in still water (possible flushing water over the gills?). Out of 20 rocks overturned in search of invertebrates (10 in riffle habitat and 10 in pools), this species was found under eight (15 individuals), 6 in riffle habitat and 9 in pool habitat.