Original: This distinction is the basis for the earliest taxonomic divisions in the Lepidoptera: the Rhopalocera ("clubbed horn", the butterflies) and the Heterocera ("varied horn", the moths).
Simplified: This distinction is the basis for the earliest taxonomic divisions in the Lepidoptera - the Rhopalocera ("clubbed horn", the butterflies) and the Heterocera ("varied horn", the moths).