Length: fly in photo 10.8 mm
The name Xylophagidae is from the Greek and tranlates as "wood eating."
Doing an internet search on the genus name "Dialysis" is troublesome, since many of the hits returned have to do with kidney treatments. Dialys is Greek for to dissolve or separate (Borror, 1960), though it isn't clear what trait of this fly group inspired the name.
Dialysis contains nine species in the Nearctic. Woodley, writing in Brown et al. (2009) states that in the New World tropics Dialysis is absent, and that in fact the only genus of Xylophagidae present there is Rachicerus. He adds that one species of the genus Xylophagus is found in Mexico north of the tropics.
Webb (1978) revised the genus. He stated that "the immature stages of Dialysis are unknown and very little of their adult biology has been described."
Look for these flies on low vegetation near streams, in rich bottomland, and in ravines.
Note that this is both the family page for Xylophagidae and the species page for Dialysis cf. elongata