This fold lies across the anterior end of the anal cleft, more or less at right angles to the long axis of the body, beneath the anal plates. It separates the anus on the dorsum from the vulva on the venter. The anogenital fold usually has setae at either corner and along the anterior margin and these are here referred to as anterior margin setae (also called fringe setae). Setae are also generally present along the lateral margins and these are referred to as lateral margin setae. On either side of the anogenital fold, there is frequently a sclerotised supporting bar that appears to be part of the underside of each anal plate, and which is probably for the attachment of the muscles used in opening the anal plates these bars extend anteriorly beneath the derm, where they frequently expand and may even meet medially