Upon first discovering this fairly translucent larva on the underside of a river rock in the Canterbury River I assumed it was a younger version of the others I was finding. But on viewing through my lens I was impressed by its absence of white gill filaments that the others had. Checking bugguide and American Beetles I am led to conclude this is the other psephenid species and genus that lives in New Hampshire, Ectopria nervosa, described as having no abdominal gills in the larval stage. I note that it is not as elongate as the Ectopria larvae already posted on bugguide so I presume those are not Ectopria nervosa.