An uncommon snaketail of small, fast, rocky streams with sand. Green thorax with black and yellow abdomen. (1) The yellow spots up to segment 7 are triangular with a notch cutout, (2) segment 8 has a blunt rectangle (not pointed), and (3) segments 9 and 10 have only small yellow spots. Unlike Boreal Snaketail (O. colubrinus), the legs are all black and the face has no black crossline. If anyone can tell the sexes of the individuals below, please let me know.