Leg charaters ■ the form of the tibial spurs and the tarsal claws The presence or absence of spines on the legs ■ Occasionally the structure of the epiphysis The epiphysis is a movable pad or spurlike structure on the inner surface of the front tibia; it is probably used in cleaning the antennae. The front legs are very much reduced in some of the butterflies.Leg charaters ◼ the form of the tibial spurs and the tarsal claws ◼ The presence or absence of spines on the legs ◼ Occasionally the structure of the epiphysis ◼The epiphysis is a movable pad or spurlike structure on the inner surface of the front tibia; it is probably used in cleaning the antennae. ◼ The front legs are very much reduced in some of the butterflies