Epeorus (Caucasiron) alborzicus sp. nov., larva: A labrum (right half in dorsal view, left half in ventral view) B incisors of right mandible in ventral view C incisors of left mandible in ventral view (both flattened on slide) D setae on dorsal surface of femora E surface and posterior margin of abdominal tergum VII F gill I G gill III H abdominal segments VIII–X I sternum IX, female J sternum IX, male K gill VII (flattened on slide) L–M gill VII (in natural position from ventral view), variability in shape.