Butterflies of the genus Polygonia are commonly called either anglewings, from the angular and ragged border to their wings, or commas from the white mark on the underside. The pattern on the underside of the wings of the sexes is noticeably different, but I find the differences between the species difficult, and it is easier to tell the sex of the butterfly than what species it is - at least when looking at a butterfly in the field. I have illustrated undersides of both male and female. The Satyr Anglewing is the commonest of our species. The eggs are often laid one on top of the other in a chain. The typical caterpillar is largely black with a broad white dorsal patch, but, in addition to the typical form, I have illustrated an unusual all-white form. The caterpillars are solitary and feed on Stinging Nettle. They hide in a folded leaf and the practised eye can easily spot and recognize the shape of the folded leaf and distinguish it from a leaf folded by the Red Admiral or other caterpillar. Winter is spent as an adult.