I found this beetle at around 7:50AM in the morning, after turning over a piece of driftwood. So they were still around, after finding a number of them a month earlier at the same location...but walking around in the sand at dusk.

A distinctive trait of some melyrids is the possession of "eversible vesicles", clearly visible here as thin reddish membranes along the anterior edges of the abdomen. (There should also be some along the edges of the thorax, though not visible here.) See the closing remarks here for more info on this interesting melyrid character.