Epeorus (Caucasiron) bicolliculatus, larva: A labrum (left half in dorsal view right half in ventral view) B incisors of left mandible C incisors of right mandible D setae on dorsal surface of femora E surface and posterior margin of abdominal tergum VII with detail of basally wide setae F gill I G gill III H abdominal segments VIII–X in lateral view I gill VII (flattened on slide) J gill VII (in natural position from ventral view) K sternum IX of female with observed variability.