Pontifex maximus pointed out that the term existed before there were any bridges in Rome and derived the word from Old Latin "pontis" (sic) meaning a powerful or absolute master, while others derived it from "potis facere" in the sense of "able to sacrifice". The last derivation is mentioned also by Varro, who rejected it, but it was the view of Pontifex Maximus Quintus Scaevola. Others have held that the word was originally "pompifex" (leader of public processions). The word "pons" originally meant "way" and "pontifex" would thus mean "maker of roads and bridges". Another opinion is that the word is a
White wagtail it still bears its original name of "Motacilla alba". The Latin genus name originally meant "little mover", but certain medieval writers thought it meant "wag-tail", giving rise to a new Latin word "cilla" for "tail". The specific epithet "alba" is Latin for "white". Within the wagtail genus "Motacilla", the white wagtail's closest genetic relatives appear to be other black-and-white wagtails such as the Japanese wagtail, "Motacilla grandis", and the white-browed wagtail, "Motacilla madaraspatensis" (and possibly the Mekong wagtail, "Motacilla samveasnae", the phylogenetic position of which is mysterious), with which it appears to form a superspecies. However, mtDNA cytochrome "b" and