Confidence: I'm as sure as I can be.
Notes: Brilliant images of a very well marked individual. The trio of A. circumscriptus, silvaticus and fasciatus are almost monochrome (yellow shading below the dark band in fasciatus), with very white sole and footfringe, colourless mucus, and a flse keel of larger tubercles along the midline. The A. hortensis, distinctus, owenii group have yellow mucus and sole. The other good feature is that this trio have the body bell-shaped in cross section, so the footfringe is easily seen from above - shown beautifully here. A. distinctus is more cylindrical, so the footfirnge is tucked under the sides. No yellow rules out fasciatus, and no black dots on the back role out circumscriptus. The broad white flanks are typical of silvaticus too.