Subfamily: Eyes are next to each other when viewed laterally.
Family ID: Head capsule mostly retracted (photo 5), long ventral lobes on the end of the abdomen (along with anal gills), paired prolegs on abdomen.
I thought this was Athericidae at first, but the mandibles would not move vertically (they would move horizontally, photo 5) and there are no lateral tubercles.
I used this site as a reference: https://www.macroinvertebrates.org/taxa-characters/diptera-larva/pediciidae/dicranota/lateral/dc1873
For the snail, not the worm
Subfamily is a guess, mostly based on the black "collar" by the back of the head, elongated anal prolegs with long dark claws & single eyespot.
Specimen preserved by freezing in bag
From the same creek sample:
https://www.inaturalist.org/observations/223300224
https://www.inaturalist.org/observations/223719511
Benthic sample of a creek
From the same sample:
https://www.inaturalist.org/observations/223565426
https://www.inaturalist.org/observations/223719511